[Vwdiesel] Fueling screw on VE pumps. --( Rabbits )

[Gavrik Peterson]

I have been following all this interesting discussion concerning the
VE Pump, and am impressed with how much people have contributed to
this.  I now want to put in my two cents.  Because my experience is
limited, I checked with the local Bosch shop to make sure that I was
not totally out of it.

>Now for the Rabbit :   The control-sleeve position at any RPM controls fuel ---"Mixture"

I think this statement is correct.

>so if you turn fueling screw in --it mechanically moves sleeve to cover bleed hole more.
>And at any load or RPM it provides engine with more fuel.

Is this true?  If you look at the diagram of the guts of the pump this
adjustment does not actually move the lever that works the control
sleeve.  It looks like it moves the 'Governor Lever Assembly' which
carries the stuff that moves the control sleeve (I think this
distinction matters).

>So turn in the fueling screw and you increase fuel at any pedal position.

I don't think that this is true.

There is a reason that Bosch calls this adjustment the 'Full Load
Adjusting Screw'.  It is true that if you turn this screw the idle and
maximum speeds will be effected.  I think this is just a side effect
that happens because adjusting this moves the 'Governor Lever
Assembly' from its previous position.  This movement effects the
tension on springs in the same way that moving the control lever does,
so it is not surprising that the idle speed changes.  One could just
as well design an injection pump that did not have this interaction.
It is my understanding that once you have readjusted the minimum and
maximum speed screws to compensate for this interaction, the 'Full
Load Adjusting Screw' will only effects the maximum amount of fuel the
pump will deliver when it is trying to deliver maximum fuel.  This
happens when the engine is delivering maximum torque.  When the engine
is at less then maximum torque the 'Full Load Adjusting Screw' has no
effect at all.

  --  Gavrik