Poor running 90Q

[Huw Powell]

> Please let me know what you find out- I have been battling this problem with
> my '89 90q for quite a few months now.  I've really gotten into everything
> pretty well- measured all fuel pressures, DPR current, OXS voltage, exhaust
> and intake paths, vacuum leaks, replaced injectors, cap, rotor, wires &
> plugs, coil checked and then replaced anyway, cleaned up all grounds I could
> find, and the bastard still won't run.  It seems like it is running pig
> rich- really stinks up the garage, smoky, and the DPR current when in closed
> loop runs to full lean signal.  And no, the cold start injector isn't
> running more than it should.  My symptoms are exactly as you describe-
> stumbles when idling, no power under load, revs like it is missing.  Once it
> really warms up it eventually dies.  Last night I had another of many 'a-ha'
> moments and thought that the crankcase vent hose might be the culprit- it
> looked pretty collapsed, but upon replacing it, no dice.  I'd really like to
> get this thing out on the road again, so if you (or anybody else out there)
> has any ideas, PLEASE let me know- I'm almost to the point of having it
> towed, and that would hurt my ego for years to come.

You are checking the DPR current and OXS voltage, but they are not 
right.  Have you tried adjusting the static mixture to see if it is 
simply wa-a-a-ay off?  Turn that little 3mm hex screw thing 
counter-clockwise to lean it out.  It might take several turns - which 
is a radical amount.

Your temp sender might be bad, too (on the top of the radiator hose 
flang on the head), and telling the ECU that it is minus 50 degrees all 
the time.

Your fuel distributor could also be pooked, in which case a used 
replacement is probably the best solution.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/