CIS-E potentiometer repair/replace

[Huw Powell]

> The plunger position potentiometer on the CIS-E box on my GTI has a dead
> spot in the idle position. I tried cleaning it and even sanding it lightly
> with 1000 grit paper and no improvement. Everything I read says you can't
> buy the potentiometer; you have to buy the entire distributor. Anyone had
> any experience repairing these or know of a replacement source? Do
> most/all of the pots out there faulty? I was thinking that if I can't
> locate one, maybe I can attach a conventional potentiometer somehow or
> maybe even expoxy the guts from another pot onto the board. Any BTDTs???.

The only experience I have is with playing around with some Audi 5-cyl 
CIS-E and E3 pots one day.  Made a test connector so we could measure 
the resistance while raising the airplate, just for fun.

Most of the ones I had around here were fine, I did turn one up with a 
dead spot in the middle, so we destroyed it for more fun.

1. They aren't installed in such a way as to be replaceable.

2. I suspect they might not be linear, or even logarithmic, which means 
substituting a homebrew pot might be a real problem.  But, no harm in 
trying.

3. If repair is impossible, you are stuck with replacing the entire fuel 
distributor assembly.

4.  It's easy enough, if you're at the junkyard (etc.) in person, to rig 
up a meter and adapter and make sure you are at least getting one with a 
good pot.  I suspect most will be ok.  You'll also be checking for free 
movement of the airplate/lever/plunger at the same time (should move 
very easily without fuel pressure to fight).

Hope this helps at least a little...

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/