Re: uhh...help!

[Michael Eck <meck@ptd.net>]

harlantr@miavx1.acs.muohio.edu wrote:
> 
> Hi. Alright, Here I am in ten degree weather trying to troubleshoot the
> cruise control on my '86 5k. I follow the bentley, and I have figured out
> that the problem lies either in the control unit or the vacuum pump. When
> I ground the correct wire terminal, the vacuum pump runs, but I am not
> entirely sure what "runs" means. It makes noise, and it sucks a little bit
> of the servo in, but not much. I hear air escaping from the vacuum motor
> itself--- Is this normal? Anyone know a way to test the control unit? I
> found one for $96 new... It is held for me till friday. I REFUSE to pay
> anyone at the shop (dealer) for diagnosis. The stories I could tell
> you....

Yes, it can be normal for the vacuum to excape from the motor. It's a
vent/release valve that regulates the vacuum pressure (suction?). If you
make the pump run by grounding pin four on the controller, ground pin
seven on the controller momentarily (long enough to see results), and if
there's no vacuum leaks, the servo should pull the pedal right down. If
that works and you've checked everything else (voltages, continuity,
vacuum hoses), then replace the controller.

HTH

Michael Eck
86 5KCSTQ   182K
88 GTI 16V  40K and parked for the winter!