[Vwdiesel] Injection pump testing for beginners 9 ----( timing piston and spring )

H.Hagar h_hagar at prcn.org
Wed Sep 29 11:34:02 EDT 2004

Lets say that you tested pump pressure and it varies with RPM.  -- BUT  the pressure
is low   lets say 25 psi.

? what to do.  If regulator valve will not bring it up ---then we take a close look
at timing piston return spring. --It is one mother of all springs for such a small pump.

Find a weaker spring or rework the one from pump ----piece of cake.

I have calibrated all kinds of instruments and gauges using acid. I suspect that
bosch has many different springs and that they are color coded. The one in my
hand is bright green.  from a 107 A  pump.

It is not as hard to do as some people say.  Next  Lorens dieselfest at Pacific
Beach --- I may show up in a white T -shirt (made by Lenora)   saying
   " I did a Bosch VE Pump ".         Is 50 dollars a barrel making you smile ?
 NO ?    A hillbilly tuned Rabbit will.    78 miles to da gallon Imp.

Hagar .

PS:  Remember you can NOT over lubricate the pump.The most economic so
far here ? --is still canning wax. (paraffin wax)

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