knock, knock! Who's there?

[Huw Powell]

> Sounds like you need to richen the mixture back to where it was. If you're
> getting the ECU light on that means it retarded the ignition as much as it
> could, but it was still knocking. Not a good thing... Best way to do it is
> to use a CO meter to adjust the mixture, but if you're O2 sensor is OK, that
> will help you find the right spot too. At idle, it should be about 40-45%
> duty cycle. You can even tell just by listening to the frequency valve.

Correct, she should first get the static mixture back where it should be 
- if it is "leaner", at WOT the engine won't get the enrichment it is 
supposed to.

But I believe Tess' car is a CIS-E3 type 89 (80Q or 90Q, 88-91).  No 
frequency valve.

Set mixture by CO, or, measuring current through DPR at idle.  It should 
cycle around 0 mA.

Tess, please confirm year/model/engine?

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/