[Vwdiesel] Gav's gov'nors

[Gavrik Peterson]

On Sat, 12 Jun 2004 16:20:29 +0200 (CEST), you wrote:

>I thought that the governor consisted of a fly-weight mechanism and
>some other grovey stuff that somehow control the amount of fuel that
>the high pressure section delivers to the injectors, and thereby,
>tries to make the engine to run at a speed that corresponds to the
>position of the speed control lever.  If this is how the governor
>works, then is not the pump doing exactly the same thing when the
>control lever is rotated by the accelerator cable as it does when it
>is resting on the idle speed adjusting screw?
>
>  --  Gavrik

>I suspect you are correct :o)
>Is your car a TD ... if so this surge could be the turbo racing??

Nope.  It is a NA Rabbit.  From the VW part number on the pump (068
130 109) Hagar says that it is the turbo version.  Years ago I
remember a diesel mechanic saying that I had a desirable pump, perhaps
because it is the type for TD.  What is the actual difference between
the two types of pumps (107 and 109)?

>The surge can only come from extra fuelling (or possibly a speed
>where the injectors are working more efficiently ????)

I am still not at all sure that I understand what is going on, but I
figure that the increase in acceleration is due to more fuel delivered
to the injectors.

It behaves like this:

  ACCELERATION
       ^
       |
       |                                 xx
       |                                x  x
       |                                x  x
       |                                x  x
       |       xxxxxxxxxxxxxxxxxxxxxxxxx   x
       |      x                            x
       |      x                            x
       |      x                            x
zero-> |xxxxxx------------------------------xxxxxxxxxxx-----> TIME
             (1)          (2)           (3)     (4)

Where: (1) Is when you step on the accelerator
       (2) Is the interval of constant acceleration as the car picks
           up speed.
       (3) Is the when the peak in acceleration occurs followed by a
           decrease in acceleration.
       (4) Now the car is going at a constant speed and the
           acceleration is zero.

>Do you get any black smoke?

None that I can see.  Perhaps I need to get serious and have a friend
follow me while I test for it.

>What about an 1/8th of a turn anti clockwise on the max fuel screw?

Never touched the max fuel screw.  Does this increase or decrease the
maximum amount of fuel?

  --  Gavrik