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so im new to VW diesels, and i got a 1.9L TD, engine code AAZ (1997 jetta), and i went out and bought the bentley manual and all the tools to time it properly. (just put a new engine in - long story there)
problem is, the wording in the manual with regards to fuel pump timing is a little iffy, i was hoping someone here could enlighten me.

heres what i remember from the manual:
obviously, setting the crank to #1 TDC is easy enuf. remove valve cover, ensure #1 cam lobes are pointing up.

install dial indicator into hole in back of injection pump, set to 2.5mm preload.
rotate eng COUNTER cw until `dial indicator stops moving`.
(this is my first problem - it never stops moving, of course, but it does reverse direction - is that what they are referring to?)

set preload to approx 1mm. rotate eng cw, stopping exactly at #1 TDC.
reading on dial should be 0.80mm, +/- 0.02mm.
(heres my second problem - is that 0.80mm, plus the "approximate" 1.0mm preload i set before? if so, thats 1.80mm. or is it just straight up 0.80mm, in which case the "approx" 1mm preload better be EXACTLY 1.0mm, or the whole thing is a **** waste of time!)

thanks for the help!

Premium Member
527 Posts
you did it already quite right. The preloading of the dial indicator shall only ensure that it is still in contact with the distribution piston inside the pump when this piston is in low position. This is where the reading of your dial indicator does not decrease further when you turn the crankshaft ccw (don´t turn the camshaft with timing belt on!). The preloading must not be accurate, but still be available with the pump piston in low position. Starting with about 2mm preload when Cyl #1 piston is in top is ok.
In the lowest postion of the piston (or lowest value of the dial indicator), you set the indicator scale (not the preload!) to zero. Then you turn the crankshaft cw until #1 piston is in top position. There should be a mark on the flywheel visible on the gearbox side. In this position, the dial indicator should read 0,80 mm +/- 0.02 mm (or equivalent in inches). This is the value I have in my Audi manual for the AAZ engine.
For the case you can not set the scale to zero, the indicator must read a value corresponding to the preload plus the 0,80 mm.
If you need to adjust the timing, loosen the attachment screws of the injection pump moderately and turn it until the reading is ok. Do not forget to loosen and retighten the pressure pipes after timing adjustment, in order to release any tension.
I do not know whether you engine has a cold starting aid. If, be sure that the lever is fully in (warm engine).
I did all that through years with my Passat (CY Turbodiesel).
Have fun,

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9,413 Posts
Yes the swear filters can be a bit aukward to set as there are many combinations but that one was a bit obvious. ;)
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