HOW-TO: Set The Injection Pump Timing
Written by Vince Waldon   
Wednesday, 01 October 2008

    This HOW-TO describes using the factory-proscribed "dial indicator" method of setting the timing on a VW IDI diesel engine.

There are other methods... by ear, using a piezo adapter on a standard timing light, using a glow-plug sensor on a standard timing light.  The static dial indicator technique is the "official service manual" method and IMHO a good way to ensure things are set correctly *before* troubleshooting further, or before refining further with a different technique.

Like all recipes you need some specific ingredients and equipment... I recommend you read all the way thru before starting.

Your comments/suggestions are always welcomed... this is how I tend do to things but I make no claims to having a monopoly on the truth !



  • Use these instructions at your own risk
  • Read them through from beginning to end before starting
  • This is how I do things… it is not necessarily the right way nor the best way !
  • Using equipment,tools, and supplies incorrectly could result in serious injury to you or your property or even death
Please note:  You can click on any thumbnail below to see a larger version of the image.  After viewing the large image, you can click on "close" to return to your spot in the text





Although it looks complicated and terrifying it’s actually fairly straightforward. There are four main parts to this procedure, in summery it looks like this: 


1)      Preparation…. pulling things off to get ready

2)      Confirming the timing belt timing

a.       Getting the engine to TDC using the timing mark on the flywheel

b.      Getting the cam to TDC using the cam lock

c.       Getting the injection pump to TDC using the pump lock

3)      Setting the injection pump timing

a.       Inserting the dial indicator

b.      Rotating the engine backwards (counter clockwise) until the dial indicator stops moving

c.       Zeroing the gauge

d.      Rotating the engine forwards (clockwise) to exactly TDC

e.       Reading the timing value on the dial gauge

f.        Adjusting the pump timing, if required

4)     Putting it all back together




Specific Tools needed:


  1. A cam lock


There are a bunch of options here. 

-         You can purchase the official VW tool (Mantra 2065A or equiv.  )

-         Many eBay suppliers carry them

-         A 3” brass hinge

-         A straight file











  1. A pin lock for the injection pump


Again there are a bunch of options:

-         The official VW tool (Mantra 2064 or equiv)

-         Many eBay suppliers carry them

-         A deep socket, metal rod, etc, that’s 0.600” or 15.35mm in diameter

-        a big bolt ground down to fit 











  1. Dial gauge adapter… one end has special metric threads on one end to fit into the injection pump, the other is the right diameter for the dial gauge to fit in


-         the official VW tool (Mantra 2066, 3313,  or equiv)

-         many eBay suppliers carry them










  1. Dial gauge


This can be metric or imperial and should have at least an inch (25mm) of travel.  The shaft needs to fit the dial gauge adapter.  I bought a cheepie and ground the shaft down to fit.










  1. 19mm 12-point socket…. needed for the crankshaft bolt.  If you have older diesel you may have the original 6-point bolt… if so, consider getting a replacement soon since the old bolts tend to loosen (hence the new design!)


  1. Sprocket puller… sometimes needed to loosen the cam sprocket.  Some people are able to tap the sprocket off with a hammer…. never ever worked for me.


  1. two sets of feeler gauges… used to make sure the cam lock is exactly parallel.  If your particular cam lock is a perfect fit you won't need these


  1. large (12")  Crecent wrench or sprocket locking tool….used when loosening the camshaft sprocket









I personally recommand the actual sprocket locking tool...  very cheap,  can't damage anything , and is also great for other sprockets like the injection pump.

Parts needed:


-         valve cover gasket

-         depending on the length of your dial gauge adapter and dial gauge you may need to remove the vacuum pump.  If so, replacing the vacuum pump o-ring is a good idea



 Supplies needed:


                       -   spray can of brake drum cleaner to make the business end of the injection pump surgically clean

                       -  shop air if you have it


Detailed Proceedure:



Part 1: Preparation


1)      car in neutral, rear wheels chocked

2)      cold start handle pushed in all the way in…. VERY IMPORTANT

3)      pull off the valve cover, exposing the cam shaft

4)      remove the timing cover on the top of the transmission  <picture of timing hole cover

5)      remove the timing belt cover 

6)      I like to pull the air filter housing… gives me more room to see what I’m doing



Part 2: confirming the timing belt timing


1)      Find ignition TDC for cylinder #1.

a)      rotate the engine clockwise until the engine is at TDC (as shown by aligning the timing mark on the flywheel









I have a dot of whiteout on the crankshaft to help me find the TDC line. 

As a random aside, if you look closely you may see some yellow and red fingernail polish as well... last time I had the engine apart I put a 4 inch strip of each on the flywheel... yellow for BTDC and red for ATDC, again to help me find the marks under dim conditions.  I also punched a mark at 12 degrees BTDC for that magical day when I finally win an eBay auction on a piezio timing adapter... those things are both rare and spendy. 


b)  and both lobes of the camshaft for cylinder #1 are pointing up (meaning that both valves are closed)









2)      Insert the cam shaft lock into the slot at the back of the camshaft.  If needed by your particular locking tool, use an equal number of feeler gauges on each side of the lock, to ensure the lock (and thus cam) are completely parallel. You may need to rotate the engine a bit to make this happen.






 cam slot








 cam slot with lock in place





3)      Confirm you are still at exactly TDC according to the flywheel… if you had to rotate the engine a bit getting the cam lock in place you probably won’t be.  If you are no longer at TDC, you need to adjust the camshaft timing:

a)      loosen the nut on the camshaft 1 turn and then gently loosen the camshaft with a rubber hammer or puller.  The camshaft has no key and so this will allow the camshaft and engine to rotate independently.  DO NOT use the camshaft lock to hold the cam steady as you loosen the bolt….a large crescent wrench grabbing on to the sides of a cam lobe works really well, and won’t scratch the working surface of the cam









you can also use a sprocket locking tool:










b)     rotate the engine back to exactly TDC on the flywheel

c)      tighten the camshaft bolt to XXX ft lbs using the crescent wrench or sprocket locking tool



The concept of  concept of "Top Dead Centre" often confuses people... because the engine has several TDC cycles...two for cylinder, and the cylinders operate in pairs. And then they start thinking about how the crank rotates twice as fast as the cam and injection pump, and what about the phases of the moon.... arggggggggggggg !

Don't let it freak you out.  We time the engine at the classic and universal defintion of TDC:  piston #1 is at the top of its compression stroke and fuel is being injected into it.  We know the #1 is at the top of its compression stroke using the TDC mark *and* having the cam lock in place with both cam lobes for #1 up (meaning both valves are closed).   We know fuel is being injected into #1 with the next step.  


4)      insert the pump locking pin into the locking pin hole (smallest one on the sprocket)  in the pump sprocket and thru to the pump mount









If you can’t get the locking pin installed this probably means the timing belt is not installed correctly.. you’ll need to loosen the timing belt tensioner, the cam shaft sprocket, and then move the belt to a new position on the injection pump so that the hole lines up.. again, with the engine at exactly TDC according to the flywheel.

Some people report that they can't always get the locking pin in during this step even though everything else goes well.  That can certainly happen if the pin is a really tight fit and you can try something else with a slightly looser fit.  You can also try loosening the belt tension so that the sprocket can move a bit (don't forget to tighten up the belt again if you do this!)

The purpose of the locking pin is to make sure you are at the #1 injection cycle *and* have the timing belt on the right teeth on the injection pump sprocket.  It's ok if you use a pin with a little slop, but if the holes are really out of whack I'd stop and figure it out... most likely the belt is off a tooth or two and you'll never be able to set the timing properly.


If you now have:


-         the engine at exactly TDC according to lining up the flywheel timing mark

-         the camshaft locked at exactly TDC with the locking bar (and two sets of feeler gauges if needed)... both lobes of #1 up

-         the pump locking pin inserted into the alignment hole


then congratulations are in order:  you’ve confirmed that the timing belt timing is perfect, and you’re ready to move on to setting the actual injection pump timing.  If not, do the procedure over again… there is NO sense timing the injection pump if the timing belt is out of position… and in fact, if the timing belt is out much it can seriously damage the engine.


Part 3:  Setting the Injection Pump Timing


1)      confirm that the timing belt timing is perfect one last time, and then REMOVE the cam locking tool and the pump locking pin, leaving the engine at exactly TDC

2)      confirm that the cold start knob is pushed all the way in.  Not kidding... be darn sure that sucker is pushed in !!

3)      remove the timing gauge cover bolt from the injection pump










You don't want to introduce any dirt into the system here so make sure to clean the area well *before* removing the bolt.  The can of brake cleaner (and shop air if you have it) will work wonders, and makes it much easier to spot leaks later on.

4)      install the timing gauge adapter and timing gauge.  You may need to remove the vacuum pump to give you enough room.









5)      push the timing gauge into the adapter such that the gauge has a couple mm of “preload”.  “Preload” means to ensure the gauge has enough travel that it will track the plunger inside the pump all the way.  You can set the preload by zeroing the gauge once it starts to move, and then pushing in the gauge an additional 2 mm

6)      insure the engine is still at exactly TDC… amazingly the engine will want to move little bits on its own as you fuss with it, and we need to be at exactly TDC

7)      Slowly rotate the engine backwards (counterclockwise) until the dial indicator stops moving.

 The timing gauge should move smoothly as you rotate backwards.  If it doesn't there's a good chance it's binding... make sure nothing is touching the timing indicator and realign things as needed.

There are several schools of thought on how to do this rotation.  The obvious way is to use the 19mm 12-point socket and a large ratchet or breaker bar on the crankshaft bolt.  Some service manuals say “don’t do this” since they are worried about accidentally loosening that very critical bolt.  If you’ve ever torqued the bolt yourself you know that this is very very very unlikely (the damn thing will often not come loose without a much bigger breaker bar, some strong language,  and a long length of angle iron bolted to the sprocket), but if you’ve not done the bolt yourself and can’t be sure it was done correctly you might want to avoid this method. Or, better yet, get yourself a new bolt and torque it properly in the first place… saving you the worry of it coming loose down the road.









Another way is to use the socket on the camshaft bolt.  I don’t personally like this method because imho it stresses the belt and can loosen the camshaft bolt, which is not torqued like the crankshaft bolt

Perhaps the safest way is to put the passenger side of the car on a jackstand, and then with the engine in gear rotate the passenger wheel.


However you do it, the trick is to make sure you have rotated backwards far enough.  It’s actually fairly obvious….as you rotate the dial indicator will move linearly until it stops.  You can rotate the engine backwards just a bit more to prove to yourself that it really has gone as far as it can go… there’s no harm in overshooting a bit just to make sure it really has stopped.


8)      zero the dial indicator... on most dial indicators you rotate the dial face








The service manual says to adjust for some preload here, but I find this just confuses people, and we already know we have enough preload.  Make it easy on yourself, and just set the gauge to zero.  


9)      slowly rotate the engine forwards (clockwise) to exactly TDC, as indicated by the mark on the flywheel

It's ok to overshoot TDC  a bit while you are trying to find it... just rotate backwards (counterclockwise) if you do .. the  point is that you must (eventually) land on  *exactly* TDC to read the timing value.

10)  read the timing value on the dial indicator









11)  compare to the required setting (in the example picture above we are a bit over 0.026"... a bit too low/retarded as we'll see below)


Again, several schools of thought in terms of what timing value to use.


The Bentley service manuals list the following "official"  settings:

Early Chassis:  (1977-1983)

1.5l non-turbo 1977-1980                                        0.88 +/- 0.05 mm

1.5l non-turbo 1980 with yellow dot                         1.15 +/- 0.05 mm

1.6l non-turbo  1981, 1982, and 1983 pickup            0.88 +/- 0.05 mm

1.6l non-turbo  1983 Rabbit and Jetta                        0.95 +/- 0.05 mm

1.6l non-turbo  1983 Vanagon                                  0.90 +/- 0.05 mm

1.6l tubo diesel (1982-1983)                                       1.00 +/- 0.05 mm


MK2 / A2 chassis:  (1985-1992):

Engine ME (1.6l non-turbo) 1985                             0.95 +/- 0.02 mm

Engine ME (1.6l non-turbo) 1986 and up                 0.90 +/- 0.02 mm

Engine MF (1.6l turbo)                                           1.00 +/- 0.02 mm

Engine 1V  (ECO diesel)                                         1.00 +/- 0.02 mm

MK3 / A3 chassis (1993-1997):

Engine AAZ  (1.9l turbo)                                        0.80  +/- 0.02 mm


Many performance tuners use the following:

-         non-turbo pumps:  0.95mm to 1.00 mm  (0.037" - 0.039")

-         turbo pumps:         1.00mm to 1.05mm (0.039" - 0.041")


 Note to those of you rockin' a Giles pump:  Giles builds in a lot of dynamic advance to his pumps and generally recommends using 0.95mm as the starting point when setting the static timing of one of his beasts. If in doubt, contact him directly and seek his advice...he built the pump, he knows what's best.  ;-)

Unlike a gas car you can’t really hurt a diesel with a little bit too much advance… you just get more noise, less power, more emissions, and less fuel economy. If you go overboard the engine will be hard starting, sluggish, noisy, and possibly trail white smoke (unburned diesel).

I personally use the upper end of both those settings.. . nothing has blown up so far.  If the engine rattles even  when warmed up, and/or it actually is more difficult to start in cold weather you have probably gone to far in the advanced direction. 

 IMPORTANT:  If you get a wacky reading at this stage (something really small or really large) STOP and PONDER !!!!   Assuming the car ran before you started this proceedure you should see a reading somewhere within the 0.8 - 1.05 mm range.  If you are way outside this range consider the possiblilty that you've done something wrong.  No sense adjusting the timing until you straighen this out.  The usual suspects are the timing gauge binding, not finding the right TDC, and the timing belt being off a few teeth.

 In fact, if this is your first time doing the timing you might want to consder repeating the steps a few more times to confirm you get the same reading.  If you get the same reading 3 times in a row you know you're doing it right !!!


12)  adjust the timing as required:

a)      loosen the four bolts holding the injection pump in place… three at the front and one at the back

Three front mounting bolts... two that you reach with a 13mm socket thru the holes in the sprocket, and one you get with a 13mm wrench on the front mounting plate:









One rear mounting bolt... the side you can see is 13mm and the other side is 15mm, reachable from below the pump thru its mounting bracket: 










b)     to advance the timing (move the dial indicator to a bigger number) rotate the top of the  injection pump towards the engine.  Conversely, to retard the timing (move the dial indicator to a smaller number) pull the top of the injection pump away from the engine.  Easy does it…we are talking small adjustments here.

Here we are at 0.039" (1.00mm)... exactly what we had in mind:










c)      once you get the correct number, tighten the pump mounting bolts, rotate the engine all the way forward to exactly TDC, and the confirm that you’re set correctly by repeating steps 9-11

d)     once you have confirmed you have the right setting it’s a good idea to loosen all four injector lines at the high pressure side of the pump and then tighten them again… this relieves any stress in the steel lines caused by moving the pump.  Again, you don't want to introduce any dirt at this stage so clean well with brake drum cleaner and compressed air.




Part 4:  Putting it all back together again


1)      remove the dial indicator and reinstall the bolt.  The service manual calls for a new copper o-ring… I’ve never had it leak but there’s always a first time.

2)      replace the vacuum pump, if you removed it to give yourself room for the timing gauge

3)      VERY IMPORTANT:  slowly rotate the engine a couple of revolutions by hand, stopping IMMEDIATELY if anything seems to bind. This confirms that everything is free to turn and confirms that the valves and pistons are not on a collision course.  It also confirms you really have removed all the locking devices !!  About once a month I read a story about someone who worked on the timing belt and then enthusiactically cranked over the engine.. bending valves in the process.  It's a real bummer to have timing work turn into a full-blown engine rebuild, and if you don't take the time to turn the engine over by hand you're gambling on your mechanical prowess.  The question is: do you feel lucky, punk ?  Well, do ya ??!!

4)      reinstall the valve cover, using a new gasket

5)      standing clear of the engine… start it up and confirm that it’s running properly. The car will probably take a bit of cranking to start and will run rough for a little while (30 seconds or so); you introduced some air into the system by opening the timing port and loosening the injector lines. If it is consistantly hard to start once, runs rough even when warm, or has a lot of smoke there’s a good chance you need to start over !!  Inspect carefully for fuel leaks at the injector hoses you tightend and the timing plug bolt.


6)      reinstall the timing belt cover

7)      reinstall the air filter housing, if you removed it initially to give yourself more room

8)      replace the inspection cover on the timing mark port on the top of the transmission


9)      congratulate yourself on completing what is probably the most complicated procedure a VW diesel has to offer !!





Comments (74)Add Comment
written by phillip, June 08, 2016
Hey i have 1997 vw passat tdi with ahu motor. I'm installing used injection pump do have to time injection pump with dial gauge or vw vcds program?

Hi Philip.. on an AHU the timing is set initally by using the correct jigs, much like the earlier engines. You then read the timing with VCDS and dial it in by rotating the pump on its mount... again like the earlier generations.

Some folks think you adjust the timing using VCDS but that's not quite it... you read the timing with VCDS and adjust mechanically as required.

HTH, Vince
written by glenn, January 16, 2016
Just wanted to say, THANK YOU! What an extra ordinary article! Good work!
written by Mac, August 07, 2015
smilies/grin.gif Very thankful manual!
written by mike, July 01, 2015
you say on a 1.9 td abl the pump is pre timed and just to lock it out , what if the pump you bought has had the hub removed ? how do you reset this , is there a specific position for the woodruff keyed shaft , why doesn't the hub have a corresponding keyway ? I hate vw vans at the moment !

Hi Mike... there's no key in either the pump or cam sprocket because getting the timing right is a matter of small adjustments... to the thousandth of an inch... which a locking key would prevent. This is a diesel thing, not a VW thing. smilies/smiley.gif

In terms of re-indexing the hub, my strong suggestion would be to find a Bosch Service Centre and have it done properly by people with the right gear and knowledge.

I say this because although I've never seen a proper HOW-TO on this on-line I did discuss it with a Bosch tech once...they obviously use their test bench but he thought one could fake it with a dial indicator and adapter, a locking bolt for the shaft, some way to figure out when #1 was starting injection, and a bunch of trial and error.

The basic idea would be to figure out when the pump is beginning to inject into #1, then using the dial indicator to figure out the pump's TDC, then backing the pump off to the desired timing value, locking the shaft with the locking bolt, reinstalling the pump in the vehicle, reinstalling the sprocket, and tightening everything down.

Doesn't sound like a lot of fun to me, particularly in the close quarters of a van?! smilies/smiley.gif

Ive never seen it documented on line but the last time I looked was a while ago... maybe someone has figured it out.

I'd still say a Bosch Service Centre is the least frustrating path however. smilies/smiley.gif



written by JIM, June 12, 2015
good day I'm trying to set the timing on my 96 1.9 TD aaz. its from a canadian model mex Jetta. the pulley for my Injector Pump is sloted and not the Pump, how do you adjust the pump timing with that?

Hi Jim... on later model AAZ pumps the slotted sprocket means the pump is pre-timed Find he right-sized drill bit to use as a locking pin and use it to index the pump with the engine and cam at TDC... no dial indicator required. smilies/smiley.gif


written by Ryan, May 09, 2015
Hi Vince- Thanks for the great writeup. Just wanted to chime in and state that I was having some issues not getting my gauge to read a value after turning the crank forward. Turns out that when you are turning it backwards- if you overshoot and go too far, the gauge will continue to move backwards and then stop (making you think that you did it correctly)

It took me a bunch of times to realise that the increments of moving it backwards and forward is VERY small, I've included a picture of my cam in the location of where the gauge stopped. If I had this picture to begin with it would have saved me a lot of time. Anyway- thanks for the best detailed DIY on this- this is gold for the first timer. Thanks!!

written by Lon, July 28, 2014
Thank you for the well written instructions. While trying to bring back a 83' Rabbit Diesel from the dead I come across your instructions. My VW has not been started since 1999 although it was driven up to the point of parking, will not start. Timing was in question so your instructions were followed and everything checks out with 1mm of pump travel and TDC on the mark as described. I found that a 1/4" drive Craftsman deep well socket fits the pump hole perfectly and a Starett Metric Vernier Caliper was used to check travel, worked like a charm with no added tool expense.

Thanks for the kind works and the good suggestions... I know lots of people have found a socket that will work as a pump lock, but it's particularly clever to use a vernier caliper to measure the plunger protrusion!

written by DW, September 27, 2013
Thanks for the write up. I used it and the Bentley to replace a timing belt and set the timing on my vanagon. Only question I was where you and the Bentley both said to push in the cold start.
Don't think I had one so we'll see how it does. Need a big picture of it with an arrow. Thanks again
written by air-cooled or diesel, May 24, 2013
i wanted to clarify one thing about using the cresent(adjustible) wrench on the cam lobe while timing.
the comment is where the wrench is facing solid side in the correct direction and your torquing the cam gear.
by the time the cam rotates under torquing (and your hand/arm give some)you have enough compression tightness on the cam gear/cam, that your timing should be set. (torque fully w/torque wrench)
rotate crank twice, checking that you have no binding, and you should be dead-on.
during this step(and i always do it this way)dont rotate crank backwards to tdc, like i posted before rotate crank forwards to exactly tdc, if you go too far forward rotate back further and then come forward stopping at exactly -tdc-(crank).
dont forget before starting to clean wrench with brakeclean and a paper towel.
written by Michael, May 21, 2013
How do I know which 1.5D injection I have currently? There are
two possibility. The initial setting was 1.0mm and the engine felt weak, I reset it to 1.20mm now and it feels a little better

The Bentley service manuals list the following "official" settings:

Early Chassis: (1977-1983)

1.5l non-turbo 1977-1980 0.88 +/- 0.05 mm

1.5l non-turbo 1980 with yellow dot 1.15 +/- 0.05 mm

Hi Michael...I've never seen a "yellow dot" pump up close but supposedly they have a big splotch of yellow paint on the cover to the advance piston on the lower part of the pump.

At the end of the day it's my opinion that the factory specs are a good starting point when the pump is brand new, but there's no harm in "seasoning to taste"... so if it runs better at the yellow dot setting, so be it!


written by Stary, February 02, 2013
Hi, nice write up, really usefull, I see you have Bentley manual, I can not get, a hold of this one, and therefore, cannot time my 1.9D AEF 47kW engine correctly, I used .85mm, but it was too noisy and knocked, then tried .65mm as BMW uses on 1.7TD, it had fair sound, but power just suck.. it barely reaches 100km/h-60mph. Also I swapped LUCAS pump for BOSCH VP37, from other 1.9D engine.. but still, car is slow, can you help me with value of timming advance?

Thanks in advance.

Hi Stary... unfortunately the Bentley that I have doesn't cover those particular engines or pump combinations. In general you can't hurt a diesel by going a bit far to the advance side, and it sounds like the engine ran better when you added advance... so I'd be inclined to add even more and see what happens. If you go too far the engine will let you know by being very difficult to start.


written by Splitbusvanatic , January 02, 2013
Hello there Vince.
D. C. here in Ireland.
Thanks so much for your Excellent write up.
I was having trouble with the timing on my 1600 n/a Diesel Vanagon Engine.
I have the 1.6d engine and rear running gear fitted into the back of a VW Splitscreen SO42.
It all started when the timing belt fell apart from old age and likely some oil contamination.
I fitted a new belt, but couldn't get the engine to run properly at all.
It was also very hard to start.
Great difficulty was had in trying to get it to idle right too.
So, I purchased a dial gauge from eBay.
And set about the task in hand.
With your guide on my IPhone.
I successfully timed the pump using your instructions.

The smile on my face when I put everything back together and turned the key.
It fired up better and quicker than ever before.

Thanks again.
D. C.
written by Splitbusvanatic , January 02, 2013
Hello there Vince.
D. C. here in Ireland.
Thanks so much for your Excellent write up.
I was having trouble with the timing on my 1600 n/a Diesel Vanagon Engine.
I have the 1.6d engine and rear running gear fitted into the back of a VW Splitscreen SO42.
It all started when the timing belt fell apart from old age and likely some oil contamination.
I fitted a new belt, but couldn't get the engine to run properly at all.
It was also very hard to start.
Great difficulty was had in trying to get it to idle right too.
So, I purchased a dial gauge from eBay.
And set about the task in hand.
With your guide on my IPhone.
I successfully timed the pump using your instructions.

The smile on my face when I put everything back together and turned the key.
It fired up better and quicker than ever before.

Thanks again.
D. C.

written by air-cooled or diesel, December 25, 2012
as far as getting camshaft sprocket off, there is a small hole on the 'inner' sheet metal timing belt guard, its forward (towards front of car and also forward as belt turns) of top of guard. this hole lines up with cam sprocket. hole fits a 1/4inch FLAT-tipped punch. with cam bolt backed 1/2 out, using a plastic hammer hit (or rapp as i would say) a few times and sprocket comes off. DO not use a metal hammer as will indent soft sprocket.
does that help? should solve that.
As for using a cresent wrench (or adjustible wrench)on cam lobe(s) to loosen and tighten, it works perfectly. i see alot of people paraniod of using one, when i first saw in bentley i was paranoid too. cam lobe surface is hardened and harder (if its good and has hardened surface on it still) than wrench. also wrench and lobe have a lot of contact surface. --Your picture of adj wrench; wrench is turned wrong way though, the adjustible 'foot' of wrench is bound to have some give in it, the other side, the solid side, will have no give in IT. there by as you torque you will have a solid surface to tighten against (this doesnt include your hand/arm). and is proper practice too. it will reassure you of more accurate timing.
One last thing, i do notice one of the instructions you give; you have the crank turning back while checking timing. while in that instance this won't be a problem; i think it cannot be stressed enough that during INITIAL timing that the last motion of crankshaft needs to be forward --to TDC-. never in reverse (backwards). this applies mainly to inital timing. if in the inital timing process you go forward (or advanced crank) of TDC, you need to rotate crankshaft backwards of TDC some (a few degrees) and come back forward to -exactly- TDC. crank rotates to the right if you face pulley from passengers side of car, or clockwise.
written by Jeff, October 06, 2012
It's important to note that rotation is as viewed from the front of the engine. I did my timing from the flywheel side and timed it backwards. This ended up being about .010" too much when I did it the right way.
written by keyanm, August 30, 2012
Thanks Vince, I want to clean it up to see where the coolant is leaking from, but it looks impossible to clean; no space to stick your hand in there. Any tricks to cleaning?

Hi Keyanm...

I find that a can of spray brake drum cleaner does a great job of cleaning random engine spots... particularly if you use the plastic pipe that goes in the nozzle. If you back it up with compressed air you can get stuff pretty darn clean.


written by keyanm, August 01, 2012
Thanks for the reply Vince. I got the 90 Jetta, and as you said, it has turbo and it is fast and responsive. However, the coolant leaks OUT from where it looks like the head gasket is (it is so greasy on the engine). The leak is drip flow, like a coffee maker, but it does add up. Does water leak out because of a blown head gasket? If the head is warped as you say, can I use my old rabbit head?

Hi Keyanm...coolant leaks can be caused by a leaking head gasket, a cracked coolant gallery in the head itself, or a leak in a gasket at a cooling flange. My suggestion would be to clean and dry the top of the engine very thoroughly so that you can tell exactly where the coolant is coming from and then decide what to do.

Assuming they are both from 1.6l 12mm stud engines the heads are somewhat interchangeable, although there's some documentation to suggest that VW changed alloys when they moved to the turbo head. Probably not worth worrying about, all things being equal, and in any event the head(s) should be carefully checked for warpage, potentially by a qualified machinist. IIRC the tolerance is something like 0.002 inches.


written by keyanm, July 18, 2012
Hello, Great write-up. Enjoyable to read.
I have a 86 jetta, engine replaced with a 1.6 rabbit diesel engine (older but less miles). Someone is giving away here 90 jetta, with a blown head gasket and also needs timing chain (she says). I'm wondering if it's a chain or belt on the 90 diesel? My own car is doing OK, except the low power on uphill climbs to the ski resort or mountain roads and difficult to start below 10F. Is repairing the 90 going to be worth the time and cost? I'm fairly comfortable with non-engine repairs.

Hi Keyanm,

Under the hood of the 90 Jetta you will find a nearly identical engine to the one in your 86...with maybe the addition of a turbo.

If the 90 has a turbo it's a very nice addition that definately adds spunk to the 50+ horses...but everything else will be the same, including the timing belt and timing belt procedure.

My only caution would be to dig into *why* the headgasket blew... if possible. Specifically if the engine overheated and caused the headgasket to go the head is very likely warped. This can be expensive or even impossible to repair (depending on severity) and replacement heads are becoming a bit difficult to find.

best of luck,

written by Hunter, June 21, 2012
Hi Vince, great write up, had a question about fuel pump pulley on my 79 vw rabbit. The pulley has 6 holes in it, 4 large and 2 small, both small holes are exactly the same size however and are directly across from each other. How do i tell which one to use or is there another way to set the fuel pump timing?

Hi Hunter... yup for some reason some of the pulleys have two holes that the timing pin can fit into.

Luckily there's an pretty easy way to sort it out. If you pull the nut off the pump sprocket you'll be able to see the spocket key and keyway... the hole to use is the one the locking pin will fit into when the sprocket keyway is pointing somewhere between 10-11 o'clock.

Just don't forget to put the nut back on!


written by Pete, May 01, 2012
This page was wonderful, thank you for putting up the info. It was concise and right on. I had to do it twice because my parts supplier gave me a belt with 2 extra teeth, so I could get belt tight but after I counted the teeth and got the straight my 82 Caddy with a 97 Jetta TDI is running sweet. Thanks again. smilies/grin.gif
written by Nick, April 01, 2012
I just installed a rebuilt injection pump on my 82 rabbit 1.6 na. The pump is from a Bosch authorized rebuilder. Pump key-way faces towards the head the same as the old pump I'm having a problem setting the timing with the dial indicator. I have the flywheel set to the diamond shaped mark, cam lobes on #1 cyl up with cam locking plate in and locking pin in the pump. I set the dial indicator pin to its mid point. When I rotate the engine counter clock wise I'm not getting any movement on the dial indicator for some distance. I have to turn the fly wheel maybe 1/2 a turn before the dial indicator stops and reverses direction. When I bring it back to TDC and rotate the pump I'm getting no movement on the dial indicator. Any ideas on what I'm doing wrong. Thanks for any help.

Hi Nick... always difficult to tell over the interwebs, but it sounds like you're doing everything right. 2 things you can check would be:
- are you sure you've got lots of pre-load on the dial indicator... you need at least 2 mm?
- any possibility the dial indicator is sticking on you?

Assuming there's no issues with the pump, my money's on the first one...even though you've said you put the dial indicator at mid-range... is the adapter jamming and fooling you into thinking you have preload when you don't?

best of luck,


written by Matt, March 18, 2012
Good write up and good comments. I'm in the process of putting on a Giles IP on my 1991 Jetta N/A. I have done a couple timing jobs on VW diesel's before and all went good. This time I can only seem to get .76mm of timing. My pump is all the way rotated toward engine. Belt timing to right on. Any ideas on this problem? Going to go back out and check my dial indicator and make sure theirs no binding. Thanks

Hi Matt:

Some reasons for not being able to get the timing value you want are:

- not loosening the cam sprocket so that it's free to rotate as you tension the belt. This results in one of the other sprockets needing to take up the slack...either pulling the crank off of TDC or causing the pump sprocket to spring forward as soon as the lock pin is removed

- not checking to see if you've wandered off of TDC when completing the timing procedure

- using something that looks like the TDC mark on the flywheel but isn't!

- a sticky plunger or adapter on the dial indicator

Just a few things to rule out... best of luck!!

written by sergio ochoa, December 16, 2011
Hi Vince, I suppose is very similar the procedure for the last generation of MK4 A4 TDI jetta in my country. the diference is the location of the pump and also the injectors . I hope you can help me with some pictures ,the year of my car is 2008
Tnks so much in advance.

Hi Sergio.

Actually your engine is very different than the one in my pictures...its a TDI engine and uses a different procedure to adjust the timing... a computer is needed as well.

Your best bet is to head to lots of discussion on setting the timing of TDI engines.


written by Cory Brandt, December 05, 2011
This is great write up! Been looking for this for a LLOOOOONNNNGGGG time. I just put another motor in my ECOdiesel (from an 81 Rabbit, mech. head and no oil squirters, higher comp). I got it running with a new belt/tension and guessing on the IP timing, definately needs fine tuned tho. Hopefully i made sense of this and get it back on the road tomorrow!
written by Dave, November 22, 2011
Today was a mild day, in Clearwater, BC and I had all of the things I had been waiting for. So, I timed the pump on my '82 Westfalia diesel according to your instructions.
It's a fiddly job but kind of fun. Initially, my timing advance was 18 thou and the engine ran quite dirty, with less power than it should have had. it's newly rebuilt.
The belt timing was bang-on, I'm happy to report, however, I had to twist the pump quite a bit to achieve an advance of 37 thou +_1. My guage hung up a bit and I went back and forth quite a few times to make sure. I should have put a bit of Lubriplate on the little shaft that connected to the dial guage.
Afterward, it ran well although I have a bit of "hunting" at idle. That improves as the engine warms up. Since the components (rebuilt pump and injectors) haven't been in action for about 3 years, maybe they need a bit of running.
On the road, the Westy had good power and it ran very smoothly. it's still a bit smoky. I suspect that, as the rings wear in, that should subside.
Thanks a lot, Vance
written by Luis Mendez, November 20, 2011
Congrats Vince,
I have a couple of questions and hope you can help me out on this. I bought a 1.6 Diesel engine but the (engine) pump mount was not included in the deal. So I am purchasing one this week. SO as I read all your info I have a clear understanding of the TDC points. Engine was running before removal. I removed valve cover and the camshaft is not to the proper alignment (camshaft lobes of cylinder 1 pointing UP). Question 1, Can I rotate the camshaft to proper alignment without the timing belt on? Question 2,

Part 2: confirming the timing belt timing

1) Find ignition TDC for cylinder #1.

a) rotate the engine clockwise until the engine is at TDC (as shown by aligning the timing mark on the flywheel


Can I just move the flywheel pulley to the TDC mark without the timing belt on?

Thank you so much,

I appreciate your help.


Hi Luis.. these are interference engines and as such if the cam and crank aren't in near-perfect synchronization pistons will kiss valves. This means its pretty challenging to rotate one independent of the other and not bump things together.

IMHO the safe way to accomplish want you want is to unbolt the 5 cam saddles in sequence and remove the cam. This allows all 8 valves to close and then you can rotate the crankshaft anywhere you want... including TDC. You can then rotate the cam to TDC and slowly bolt it back down, again in sequence, and carry on with the timing sequence. "The cam at TDC" means that both lobes of #1 cylinder are pointing up as in the pictures, and you've got the cam lock in place and it's parallel to the head.

Having said all of the above... if you are very very gentle you can slowly rotate the crank by hand, stop when feel a piston hit a valve, rotate the cam a bit, rotate the crank some more etc etc etc... and eventually get to TDC. I just find it faster and safer to remove the cam.

hope that helps,

written by Adrian, November 06, 2011
Good post I've did my hard and this process worked to set timing. I am getting a lot of black exhaust deposit on the back of my Jetta. I think it may be running rich. Do youvknow how to set the air fuel mix?

Hi Adrian...there really isn't any "rich" or lean" when it comes to a diesel engine, because it always has more than enough 02 since there's no throttle plate and a wide open air path.

Some soot is normal in a diesel's tailpipe, but if you're getting excessive black smoke that's coating your bumper you are probably overfueled. You don't mention what engine etc you have, but the causes of overfueling including one or more injectors in poor condition, boost leaks, or a pump calibration issue. The latter is pretty rare since the adjustment screw is locked with a collar, but if you google "max fuel screw" you should be able to find some info. I'd look at the fuel screw only after eliminating all other possibilities.. it generally doesn't just fall out of adjustment on its own.


written by Dave, October 24, 2011
Awesome Vince......Thank You!
I just ordered a dial gauge adapter from Samstag Sales that you referenced!

Hope my 1980 1.5L timing belt change (and clutch replace) go well smilies/grin.gif smilies/grin.gif
written by Dave, October 24, 2011
Vince....great write up....thank you very much!

I'm doing a 1980 Dasher, and found the TDC access on the drivers side of the transmission bellhousing. I'm finding a pin whare the TDC should be (I think)....would that sound right? I've posted a pic on the TDI forum, and several of the job I'm doing on a photobucket page I've created for this job documentation.


PS: the link for the VW tool(s) is great, thanks!

Hi Dave... thanks for your comments. Unfortunately I don't have any Dasher experience to offer here...hopefully someone from TDIclub will chime in. My only add would be to re-iterate that you turn the engine over by hand once you've finished the timing belt job...the idea being it's much better to find valve interference by hand than with the starter!

Best of luck,

written by Dave, October 21, 2011
Thanks for a wonderfully articulate set of instructions. I've rebuilt five of these pre-90 engines and have never set the pump timing myself.
One question...On these older engines, I've consistently asked myself which direction is better when it comes to rotating the timing belt tensioner bolt. One way moves it closer to the cam wheel, the other moves it away. The last time, I believe I rotated it closer to the cam wheel. It seemed to tension the belt more consistently ie. without leaving a bit of slack anywhere on the belt. Also, it didn't seem to forced the crankshaft to rotate either way. What do you do ?
This last time, just a few days ago, I timed it on the bench, just after putting on the head. Things were a bit stiff and everything stayed where it was supposed to. The engine started and it runs smooth, but dirty. I know I have more work to do.

Hi Dave...thanks for the comments.

The tensioner is designed to be tightened in a clockwise direction according to the Service Manual. Kinda makes sense to me...tightening it in that direction gives the timing belt the maximum contact with the cam sprocket.


written by Metter, October 16, 2011
Thank you for all the information, I am new to diesel mechanics and now i have a good idea about the timing and what is required. You are a good man taking the time to make our lives a bit easier. Thank you very much !
written by rob, August 17, 2011
are there any crank pulley marks?
i have an AAZ installed in my VW syncro vanagon so i'm afraid i won't have the same flywheel markings that you posted. i'll be installing a rebuilt pump soon and want to make sure it goes on smoothly.
thanks for any insight

Hi Rob... I've never seen a TDC notch on the crank pulley...I've read they have been occasionally seen. Even if you have a pulley with a notch there are two problems:

- the pulley can be installed several ways
- the circumference of the pulley is very small compared to the flywheel, so not a very accurate way to line up TDC. With these being interference engines even a small misalignment can be a big problem. ;-)

Unfortunately Ive no direct experience with this.. a bit of googling might turn up how Vanagon conversions work around this... a dial indicator thru an injector hole might work?

written by Ken, August 16, 2011
Hi: In one of the posts here May 5/08 John mentions that a mechanic changed a clutch and didn't put the flywheel back in the right position. Is there a proper procedure to ensure the flywheel and clutch is installed in the correct position if it was not marked when removed. I have a '86 Jetta TD which had the clutch replaced by a mechanic 2 yrs. ago. It is due for a timing belt change but now after reading this I am wondering if that could happen easily. Are there no dowels or something to prevent this. I have never changed a timing belt on these before.


Hi Ken... the pressure-plate holes are asymmetrical so it only fits one way on the crankshaft, and then there are dowels so that the flywheel only attaches to the pressure plate one way.

Unfortunately if the mechanic is in a hurry with the impact wrench it is possible to not have the dowels aligned and just force it all together with too much torque.

written by Adriaan, May 15, 2011

I am currently working on a 91' diesel jetta. I was able to find a fuel injection pump for a good price and have installed it. I have set the timing in accordance with this website. The issue that I have is a bit embarrassing after the work I have already done.

Do I have to prime the injection pump with diesel in order for the car to run?

There is no fuel running through the pump or even past the fuel filter.I have tried turning it over for a while and it won't start.

I wanted to know if it's possible that the fuel pump at the tank is/or has been broken for a while but because the system was pressurized it went unnoticed.

I would really appreciate some tips and instruction and thanks for taking the time to read this.


Hi Adriaan... the system is designed to be self-priming, but occasionally needs a little help, especially if the pump has a lot of miles.

To help the pump prime:

- prefill the fuel filter with fresh diesel
- prefill the pump with fresh diesel. I generally pour it in the inlet hole using a small funnel
- crack open the injector lines at the top of the injector a bit... laying a rag across the tops to prevent fuel from splattering too far.

NOTE: the fuel is under high pressure and is flamable.. wear skin/eye protection and have a fire extinguisher available etc etc

- turn the engine over 20 seconds at a time (resting for 40 seconds to allow the starter to cool) until fuel starts to dribble out the injector fittings.

- when it does, tighten the fittings back down, start 'er up, and drive away!!

If after the above you are still not getting fuel at the injector lines you can:

- confirm you are getting 12V at the stop solenoid... the brass cylinder on the cast iron high pressure side of the pump
- apply suction at the Out fitting with a brake bleeding vacuum pump to check for occlusions in the lines.

Good luck!

written by nathan , March 26, 2011
Thank you so much. My vw runs again!
written by Jason, August 03, 2010
Hi, I replaced the pump my Rabbit pickup, all of the timing marks line up perfect but still pours white smoke when running. I have rotated the pump in both directions and it still smokes just as bad. Im out of ideas?
Thanks Jason
written by Rick, June 26, 2010
Hi mate
Great read for the IP timing,i like your methodicalness to everything,do you happen to know what the setting is for the IP timing on my VW T4 1.9TD 2001 ABL Bosch pump vernier pulley type.
written by Robert, May 12, 2010
Great write up with very useful pics. Do you have any experience with trying to set the timing on 84 rabbit diesel that might have gasser flywheel. I am not finding the usual tdc mark. Rather, I have 0 and marks for before and after tdc. Do I use the 0 mark? Or is it 6 degrees before tdc?
written by Harald, April 24, 2010
Thank you so much for this excellent guide, Vince. It has really been helpful. A while ago, a workshop managed to bust my diesel pump during emission test at MOT. They denied responsibility and acted like bastards, tried to fool me once or twice with bull shit fault diagnostics.

I got better advice on the internet, and ended up swapping the pump at my self. Pump timing ended up at 1,01 mm. I wonder if it will consume less diesel if I try 0,90? Car is a T3 with 1,6 TD (JX).

Hey Harald... thanks for your comments.

My completely personal opinion is that the engine will provide the best fuel economy when it's got the optimum amount of advance... it's producing power most efficiently and so the driver uses his right foot less... imho the right foot being the single biggest cause of poor economy!!

So, I think if your engine is happy with the advance you've got and you retard the timing you're likely to see your fuel economy get worse rather than better.

Of course there are many other factors... the static timing setting is really only the beginning of the timing curve... but it's been my experience that within reason a bit more advance is better, economy-wise, than a bit less.

written by Luke, January 14, 2010

If you have a large "crows foot" socket, you can stick it in the holes on the side of the cam sprocket, then hold onto the crowsfoot sideways with an adjustable wrench. This holds the cam sprocket very securely and lets you be comfortable that you're not damaging the cam lobes. I trust you and Tyler know what you're doing, but even looking at that picture of the wrench on the lobe makes me nervous.


Great additions Luke... thanks!!

written by Luke, January 14, 2010
Thanks for the great write up, Vince.

In case it helps anyone shopping in advance, the groove in my camshaft (and therefore the thickness of the brass hinge you want) is almost exactly 4.5mm. This is on a CR engine with 11mm head (early 81), I don't know if it differs on other models. I purchased a 3 1/2" brass hinge from Gateworks at Lowes; it needs to be folded closed to measure correctly (ie, each wing is only half that) but it folds totally flush with itself so it's a non-issue. I've used the proper VW tool and this works every bit as well.

Also, in case you're here because you're also doing the head gasket, using a 2 1/2" U-shaped exhaust clamp from the autoparts store to remove/install the C spring clamps that hold on the toilet bowl style exhaust header works PERFECTLY.


written by mitch, October 20, 2009
Heh Vince,

Thanks for this page. Really helps out.

FYI Baz says the timing setting for the AAB engine is 1.00 mm +-0.02mm.

Thanks again for all of your help bro.

written by Dan, September 01, 2009
Vincent, just replied to your very helpful post on VW Vortex...I have got a far as timing the pump...need to get a dial gauge, and will then follow your advice. Thanks again dude!

written by Ken, November 22, 2008
Increasing the timing a bit, boosts power, but what does it do to fuel economy?
written by iain ambrose, August 25, 2008
Worked out what it was smilies/cry.gif
I was using the wrong marking as TDC.
Now I have doubled checked and noticed there are two raised notches with the TDC marker in the middle.
Stupid mistake but no damage done.
written by iain ambrose, August 25, 2008
Worked out what it was smilies/cry.gif
I was using the wrong marking as TDC.
Now I have doubled checked and noticed there are two raised notches with the TDC marker in the middle.
Stupid mistake but no damage done.
written by iain ambrose, August 23, 2008
I been trying to get my 1.9 AAZ golf repaired after a cambelt failure.
I have rebuild the head and put everything back together ok.
The problem I have is getting it running.
I have followed your guide and have been able to get it all timed up including the pump.
When I try to start the car it turns over, fires up and immediately dies. If I floor the throttle it again fires but this time dies with a bit white smoke coming from the engine bay.
Oddly enough, whilst messing around I deliberately put the pump one notch out and the car started up no problem.
There was obviously a problem though as it was knocking badly, but it did drive fine albeit noisily.
After a fair drive I rechecked and found a follower had been broken off!
If the flywheel was bolted on wrong surely all the valves would have been destroyed again?
I did have a look when the head was off and the TDC marked seemed to match TDC on cylinder number 1.

Any help would be greatly appreciated.

Many thanks,

written by Graham, August 05, 2008
I just bought a replacement ip for my 97 1.9TD AAZ. It's a second hand unit. Unfortunately, someone has loosened the pulley via the centre bolt so that the pulley can spin on the shaft without the pump moving. (timing referance mark will obviously not line up for the initial setting due to there being no keyway on the shaft. Hope you understand this, very difficult to describe)
Is there a way to set up the pump so that the pump locking pin can be fitted to the pump in the correct position ie how do I refit the pulley in the right position on the shaft? Many thanks, great write up. Regards, Graham

Hi Graham:

I just got my first AAZ with the adjustable pulley and haven't played with it much. However, while looking at it and talking to a guy who does this for a living it appears that you can set it the old-fashioned way (dial-indicator). With enough fooling around you might be able to get the index pin setting back. If you post this question at someone with more recent experience might know how to set the pulley on the bench... that's how the pros do it evidently.

If you do find out how to do it on the bench I'd be very interested to know !!

written by Will, July 28, 2008
I have a 95 Jetta 1.9 TDI and I let the shop replace my water pump last week. Immidiately after it started rough and smokin' out the rear pretty bad. Now the injector pump is dead. Did the shop cause this? It ran beutifully until they did the water pump.
written by matt mcbride, July 26, 2008
i'm in the process of rebuilding my 1.6na and i can't seem to figure out how to put the ip in the correct position to start the timing process. i don't know if the ip has been turned, so i don't know where it is to begin with. that may be confusing...but i have the engine at tdc, so is there a measurement with the dial gauge that i can put my ip on to start timing the engine?
thanks matt
written by Ricardo Ramirez, July 15, 2008
thanks for the reply on the 1992 Jetta TDI it's very helpfull. I also was able to get a second opinion and they were also figured something with the cooling system or thermostat. I put in a new radiator and the fans are working properly. So we are down to two things, thermostat or perhaps the timing? Other than no power when the timing is off, it would not overheat? The car heats up not even with in 10 min. Dangerous level. I'm trying to keep the car only because it has 58K miles on it, I've purchased it when it had 12K, never had problems, until the fuel pump started leaking. Had it serviced, along with changing of timing belt. Now overheating. Any other suggestions?

I've personally never experienced poor timing causing large temp problems... certainly not to the point of overheating.... usually there are other timing symptoms (large amounts of smoke, for example) that are far more evident.

At this point I've be inclined to pull the thermostat and test it (the Bentley has the procedure but basically you drop it in a pot of boiling water and ensure it opens). I wonder if it isn't jammed partially or fully closed... 10 minutes sounds about what you'd expect if that was the case. If it seems iffy they are cheap to replace.. just make sure you test the new one in boiling water as well... they have been known to fail new and that would send you on another goose chase for sure !!

written by Ricardo, July 14, 2008
Just had shop change timming belt on my 1992 Jetta TDI, ran the car was very sluggish, car heated up and blew head gasket. Mechanic replaced head, etc.. Car is still heating up. Mechanic is not familiar with diesel cars, so I'm thinking from what I've read that timinig was set wrong and is cause car to heat up. Am I correct in this regard? Your feedback would be appreciated. I'm actually getting a copy of this page to take to him so that he sets the timing correctly.

Hi Richardo... hmmm... you're not having much luck !!

My experience has been that diesels are not particularly susceptible to timing issues causing big heat problems... at least directly. More often mis-timing causes a lack of power which causes you to drive hard which generates more heat.

In your case you've replaced the headgasket which is a common cause... I'd be inclined to dig into the cooling system more. Things like: Does the rad fan come on ? Does the lower rad hose get hot (indicating that the thermostat is working) ? When was the last time the thermostat was replaced ? Is there good flow of coolant thru the rad ?? When the headgasket went did it clog the engine and rad with oil ?

Certainly the timing needs to be accurate for proper engine operation, so it's good that you're going to ensure your mechanic is setting that properly, but I'd be more suspicious of an issue with the cooling system itself at this point.

Just an Internet guess... best of luck !!

written by Jim (subsonic), May 28, 2008
I am having a problem with the timing belt. I have the Injection pump pulley locked in the correct location, the cam is locked at TDC, The flywheel mark is sitting directly under the TDC mark arrow, verified as correct while the head was off. When I set the belt tensioner to the correct tension, the mark on the flywheel moves either to the left or right, depending on which way I move the tensioner while adjusting it. It's not off by a lot, 1/2 a cm approx. I have pulled the belt off and adjusted it 3 times, I get the same thing everytime. Suggestions?

Hi Jim... my experience is that this means you need to loosen the camshaft sprocket so that it can rotate and take up the slack rather than the crankshaft rotating.

If you've already tried that then my other suggestion is to be really really sure you have the timing belt in exactly the right teeth on the sprocket... it should line up !!

My money is on loosening the cam sprocket so that its free to rotate... let us know what you find out !!

written by Kevin M., May 27, 2008
Thanks for the great info!
I have one thing to add. If you ever replace the IP pump with a rebuilt, It is recommended to prime it first with diesel. Otherwise you void the warranty and you will cause damage to the IP. Crank it over with (YOUR HAND) and add a little diesel to the pump. I believe thats correct. Don't quote me on this. It should say in the shop manual for the correct priming instructions. Good luck with everyones project!!!!!

Hi Kevin... thanks for your comment.

The injection pump is self-priming (comes in handy if you ever run out of fuel!) but I can see the manufacturer of a new pump wanting you to fill it so that the internals are not bone dry when you crank it over.

Filling it is one way... my personal favorite is to apply suction at the "out" banjo fitting (a brake bleeding pump works well) until a bubble-free stream of diesel comes out. This primes the entire system: lines, filter, and pump, and makes sure that everything is completely ready to go when you attempt your first start.

Again.. thanks for your comments !!

written by Philippe, May 25, 2008
Thanks Vince for this remarkable guide . I found your timing step by step description far superior to any manual or web site I have read so far. I also want to thank you for your contribution to the IDI-TDI forum.

Thanks for your kind words Philppe... it's a fun hobby full of people that love to share... I've learned tons from many many other diesel enthusiasts and I think it's our duty to keep the VW diesel torch lit !!!

written by john, May 23, 2008
well we have arrived at yet another problem,as far as I can tell all the parts are original, seems that the pump isn't aligning right,if you are looking at the engine from the passenger side top,it appears that the shaft is facing a few degrees from upper right to bottom left...thus allowing the pump sprocket to run the backside of the this pump also has a litle play in it,,in adn out and after the gear is on a little wiggle,not much,but enoug. I am thinking now tht someohow the shaft is crooked,not the plate,this is even after that bottom olt is in..I am not sure how long it ran with the bottom bolt out,but now that all new parts are in I believe that the pump shaft is crooked,if that is possible.any suggestions would be of great help here now..thansk tons

Hi John:

Always hard to know exactly what's gong on over the internet, but if you are pretty sure the mounting bracket is straight and you are seeing some free play in the injection pump shaft itself the usual culprit is a worn shaft bushing. They are made of bronze and wear over time.. particularly if previous mechanics have over-tightened the timing belt.

The good news is that the bushing is cheap... the bad news is that the pump has to come out and the new bushing will need to be reamed for a precise fit.. so a precision hand reamer is required. Not a hard job but a bit time-consuming.

Lots of discussion on and about the procedure if you're considering your options.

best of luck,


written by Philippe, May 23, 2008
Vince, this is a remarkable page. I suggest the writers of Haynes and Bentley manuals should read what you have written and learn. Your presentation is clear, logical, straightforward. I think that your academic teaching background shows and you know how to relate to the pour souls such as myself who try to improvise themselves backyard mechanics. Thanks also for your steady contributions to the TDI-IDI forum.

Napanee, Ont

Thanks for your kind comments Philippe... it's a fun hobby and also an important one... IMHO diesels have some significant advantages to the planet in an era of depleting crude supplies and increasing focus on the environment. And then there's the fact that they are fun to play with !

Thanks again for your comments.


written by john, May 22, 2008
oops spoke too the vw all timed and was hard to start but I got it alt or belts or covers,had to make sure it ran first...1 slight problem,for some reason the gear on the injection pump rubs the upper part of the bracket that holds the pump..hmmm,,I am missing the bottom bolt I hope to have this remidied tomorow morning..any clues here?

Hey John... that doesn't sound good... if the rubbing is being caused by misalignment and the belt suddenly takes offence and pops off... BANG !

I'd be inclined to finish the job of putting the missing bolt back in place and see if it makes a difference once everything is bolted down. Rubbing means something is wrong for sure.... are any of the parts swapped from something else ??

written by Mike, May 06, 2008
hi, with the help of your how-to my friend and i managed to time up an old jetta td engine that is replacing the crippled one in my golf gtd. one thing we havnt done yet is set IP timming using a gauge, we just slotted the pump off my original engine over the marks left by the old pump bolts. it starts first time and runs perfectly so do i still need to get the pump timed using the guage or should it be ok? thanks.
written by john harris, May 05, 2008
Hey Vince-a quick note here..we're going to use the gauge on it tomorrow..found out that at some point in the past the lil Rabbit had a clutch change and teh "mechanic" didn't put the flywheel back on the right position...after removing the head and bringing #1 up to TDC,we made a mark on the flywheel,put the head back on and were able to turn the engine over( BY HAND!) then with the starter.looks good so far..thanks tons for all your help
written by john, April 30, 2008
thanks Vince,,we'll try that tommorrow..had a hard time getting a small screw-driver in so I was using a coat hanger..then peice of welding wire...still didn't detect any movement..but will try pulling the head off again at $40 a pop for gaskets..thanks again
written by john, April 30, 2008
nice layout,,but.......... what happens when the flywheel is at TDC, the cam is at TDC ,,,put the belt on,flywheel still at still locked...and try to turn te motor over,,a few inches and BAM locks tight against the valves?..what am I NOT doing here? thanks

Hi John... hey good for you for turning it over by hand first and discovering you have a problem... lots of people use the starter to discover these issues.

If you are really really convinced that you have all things in alignment then 99.9% of the time the issue is that your TDC mark on the flywheel is wrong. This can happen for a number of reasons: someone used a gasser flywheel, someone replaced the flywheel and didn't put it in the right spot (it will bolt on several different ways if you use an impact wrench!) or the mark you think is TDC is actually something else.

A valve that is stuck down is really the only other option and that's really really rare given how stiff the springs are. You could pull the lifters and find out, but I'm betting on the flywheel. Heard the story from other people many many times.

The trick now is to check your TDC mark and/or make a new one. The IDI has precombustion chambers which make this a little difficult, but you can pull the injector and glowplug from #1 or #4 (I'd use #4 for ease of access) and insert a long thin screwdriver or wire as a probe to detect the top of the piston's travel. Because the crank can wander quite a few degrees at TDC without appreciable piston travel the most accurate method is to use the screwdriver/wire as a stop that halts the piston about an inch below TDC. Approach the stop from a clockwise direction and make a mark on the flywheel. Back up the engine and approach the stop from the other direction, make a mark on the flywheel. TDC is now exactly between the two marks.

Not fun... sorry about that. But at least you didn't drive your valves thru your pistons by mistake in the meantime !

written by bill, April 06, 2008
If the timing mark on the transmission is lined up, does this mean that #1 is at TDC everything (timing belt is completely off)

Hi Bill... nope... TDC for #1 is a combination of (1) the engine at TDC, by lining up the flywheel timing mark visable thru the transmission and (2) the cam at TDC for #1 by having both lobes of #1 pointing up and a cam lock in place.

So if replacing the timing belt you would ensure both of the above before installing the new belt. Note that you shouldn't rotate the cam into position with the engine at TDC because two of the pistons are at the top of their travel and you may get valves touching pistons. Best to lock everything in place before removing the old belt, or unbolt the cam so that it's not compressing any valves, rotate it to TDC, and then bolt it back down.

written by bill, April 06, 2008
how do you pull the top of the injection pump away from the engine.

Hi Bill... there are 4 bolts that hold the injection pump in place. These bolts are in slotted holes, so with the bolts loosened slightly the pump will rotate, and you can move the top of the pump closer or farther away from the head.


written by Ian Slugoski, March 17, 2008
Vincent: I would like to thank you for all the help. I have it runnung now. But I had bad luck with the timing. (It did start right off though ) I seem to get a lot better just by ear. Lot more power and better RPM and no power fade at the top RPM. Your pic were a great help.. Oh one last thing. It is a good idea to look at the crank shaft to see it the key has not wecked the end of it. And replace the timing gear sprocket on the crank. My next project is replacing the rear engine. seal. Any hints. Of course this on the other Jetta. And thanks again. Ian

Hi Ian... thanks for the comments. The mainseal is pretty straightforward... two tricks:

1) coat both the flange and the new seal with lots of grease so that it slides on smoothly

2) some people like to wrap the flange with a layer of plastic from an icecream bucket or the like... they form the plastic into a funnel shape so that the new seal is applied smoothly. If you search on you'll find a couple of threads with pictures that may help.

Good luck !


written by Tinker Toy, February 15, 2008
Nice writeup; I can see lots of work invested in this and for no compensation except to make the world a better place, but it needs one clarification that I can see. It should be made clearer that the TDC indicator on the flywheel is a hollow hemisphere; at least that is what it is on my 1986 Golf.

Hi Tinker Toy.... good addition... if you ever take a picture and can share I'd like to add it for sure. In the meantime I mention it in the text.

thanks for the comments,

written by burn_your_money, February 11, 2008
In reference to Dan's comment, if the cam is 180 degrees out you can not insert the looking tool at the end of the camshaft because the slot is actually below the surface of the head

Hey Tyler... yup you're correct... the slot in the cam is not dead centre, so it can only be inserted when the cam is at TDC for #1... both lobes up. I haven't checked lately to see if a real thin lock (like a thin file or hinge) could fit... will have to check. Good catch.

written by Andy, February 10, 2008
Vince, lovely write-up. However, when I clicked on "read more" all the code shows up (with the pictures). email me if you want the screen dump.
I just pictured all the "visual learners" (like me) seeing this and having a small panic attack at the code being the IP timing instructions smilies/grin.gif

BTW, where did you buy your IP tool? I picked up a dial indicator from princess auto...


Hi Andy:

Hmmm... that's weird.. just tested it and it's workin' fine from Firefox and IE for me... what browser are you using ??

I can't remember where I got my IP adapter but I suspect it was Samstag Tools... they sell all the specialty VW toolset.

written by dan, February 09, 2008
hi, you say to make sure the cam is perfectly horizontal.. but can it be either way obviously it can be one or the other turning 180 degrees. be great if u could help.. smilies/smiley.gif

Hi Dan:

Ah, but I also say make sure both lobes of #1 are up.... so it's the combination of both lobes being up *and* the slot being level that makes the cam at TDC for #1. ;-)

written by Ian, February 05, 2008
I have a Jetta I bought that some one timed wrong and the valves hit the pistons. It did not do any damage to the pistons. But bent the valves. I have the the head repaired and now will be putting in back together. Is there anything I should be dooing to start the timing job different that what the book or what you have said here? I have all the special tools I need but never timed one before. I do know how to do John Deer tractor. So I have the bacic idea. Thanks for the help so far. Ian

Hi Ian:

I think the most important thing is to rotate the engine manually a couple of revolutions when you are done... and STOP if anything binds. If you do that you are safe... worse case it won't run well when you're done, and so you just start over or ping one of the forums for help. People that get themselves in trouble do the timing and then crank the starter only to hear loud expensive noises under the hood !!

written by vince_w, January 30, 2008
Great comments Tyler... some additional pictures are pending and I'll add in your thoughts where appropriate.... thanks for helping improve it !
written by burn_your_money, January 30, 2008
Nice writeup Vince. Couple of things I think you should add:
- mention that it's a good idea to practice getting the pump's current reading before loosening any bolts. If the car is running the engine has to be somewhat close to spec ~1.00mm. I remember the first time I used the timing gauge and I was getting like 2.00mm advance so I'd try again and would get like 0.10mm advance. If you can't figure it out, don't loosen anything.
- Make sure there is nothing touching the gauge when checking the timing. It will bind in the shaft and give false readings
- "a large crescent wrench grabbing on to the sides of a cam lobe works really well" I think this needs to be reworded or a picture showing what you mean
- Step 4 of part 2 - I usually can't get the pump lock in place with everything else locked in place. As long as the pump is at 1.00mm (or whatever you are aiming for) at TDC it doesn't matter if you can put the locking tool in or not.
- mention that when checking the timing it is fine to go past TDC, simply rotate the engine CCW to get it back to TDC. The gauge reading will still be correct
- expect the car to start hard the very first time you attempt to start it. Air is introduced into the pump when you remove the bolt to insert the timing gauge. You should mention to be extremely careful to not introduce any dirt into the pump at this stage
- Over advancing the timing will mess up the engine, and it doesn't have to be that far advanced to do it. The specs you list are definitely in the safe range though.

I love the write up and pictures, it's all very clear and easy to follow.
Well done
written by Vincent, January 20, 2008
I've lost every eBay auction I've ever seen for a dynamic timing device so have no experience there... in my mind it's probably superior in the end become it compensates for pump wear and shows you other things... like how stable the pump is firing.

However, for 75 bucks you can equip yourself to do timing the way the original VW engineers intended... probably a OK place to start.
written by Fred, September 30, 2007
which do you recommend... static timing or dynamic

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