I agree that the description in Bentley is confusing. The problem is that
they tell you what do to, but do not motivate why or explain how the
procedure relates to the function of the pump.

In addition to Dana's excellent clarification let me add:
Look at the injection pump drawing on my page (link below,
click on injection pump).

Find the cam plate in the drawing. The "bumps" on it is what drives
the plunger in and out.

The purpose of the first several steps is just to make sure that
you move the cam rollers to a point between the bumps and then
you "pre load", ie make sure that the dial gauge is in contact with the
plunger. All this is so that you start your measurement from the 0-lift
reference point.

The last step; the movement back to TDC is what measures the lift. (and should
be done precisely by sighting TDC from straight above)

Cheers,
Martin
--
Westy 1.9l Turbo Diesel
Quantum 1.6l Turbo Diesel

New and used parts for sale, gas and Diesel:

    http://www.cs.yale.edu/~jag/vw/forsale.html

Martin Jagersand                 email: vwjag@hammer.cs.jhu.edu
Computer Science Department
Johns Hopkins University

        Slow down and visit the VW diesel Westy page:
          WWW: http://www.cs.rochester.edu/u/jag/vw
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   From: Travelbike@aol.com

   Just got a timing gage and have read the Bentley Mannual a few times.  Just a
   few questions on the procedure.

   Step 1 - Turn crankshaft till the TDC mark on flywheel aligns to pointer at
   the bell housing hole with all valves closed.
   STILL OK to this point.

   Step 2 - Remove timing check plug.  Screw in tool till gage till it indicates
   2.5mm
   Still OK

   Step 3 - Using wrench on Crank bolt.  Turn crankshaft counter clockwise
   normal direction till gage stops moving.
   Question - As you turn the crankshaft,  should the reading on the gage
   increase from 2.5mm going up ?  My assumption is yes since the injection pump
   is moving back in preparation for the plunge to TDC.

   Step 4 - Readjust the dial indicator so you can zero it with a 1mm preload
   Question - this is where I get a bit confused.  At this point, do you just
   turn the dial face so that the arrow points to Zero on the dial face ?

   Step 5 - Turn crankshaft till TDC in normal direction.
   Dial should read to about timing limits in the mannual (.90-1mm for 84 NA).

   In short, is  the procedure done so that we can check that the plunger travel
   from step 3 to step 5 (TDC) is about 1mm max  for an 84 diesel NA ?

   Sorry for this stupid sounding question. Thanks to all  for any help