Re: ...the mystery of the stalling 20v Coupe Quattro

[Andrew Duane USG/PE <duane@zk3.dec.com>]

Hairy green toads from Mars made Peter Schulz say:

> My frustration with the off-load stalling of my CQ continues...
> 
> To reiterate, my coupe quattro will stall randomly when the car 
> is taken out of gear, as when coming to a stop. RPMs drop to 
> 0, and then the idle restabilizes.  Sometimes.  Other times
> it completely stalls out. The is most evident
> when, for example, pullin into a parking spot...This happens
> on Dry days and wet days, engine hot or cold.
> 
> I've removed and cleaned the ISV repeatedly with brake cleaner
> and carburetor cleaner ( It's two years old). I removed and
> lubricated the solenoid from the ISV
> I've cleaned the contacts. Chris Semple at Autobahn downloaded
> the fault codes.  They came up 4444 (ok).
> 
> The car has the updated crankcase breather hose.  I've tried the 
> butane torch (unlit of course) check on the vacuum lines. (at least
> the ones that I've been able to identify. Bentley is NOT alot
> of help here.)
> 
> When I disconnect the ISV lead, the engine immediately bucks, then 
> stalls.  If I reconnect it before it completely stalls, the car 
> idles normally.  Without the ISV connected, the car will not start.
> 
> When it's not stalling the car idles normally.  No wander, no drift.
> O2 sensor is two years old. Gas filter is 1 year old.  I usually run 
> the car on Texaco 93 octane.  Trying different gas and different 
> stations has not made a difference (tried Mobil for a while). Cap,
> rotor, plug wires, plugs are two years old.
> 
> HELP! My wife refuses to drive the car because she's afraid of it 
> stalling repeatedly in traffic.

My wife's 90Q20V did this for quite some time. Did all the same stuff.
No help.

Finally, last spring, we replaced the fuel pump 'cause it was getting
noisy.  Also put in a new fuel filter.

Voila!

Fixed.

We have noticed lately that the warm start problems that preceded the
decline into the off-throttle stall are coming back a little bit.
Chris couldn't really find anything, but suggested that replacing
the fuel filter is a cheap/fast preventative item. Bosch says that
it only takes one tank of crappy gas to clog up a filter.

I may swing by Northern Foreign Auto next week to pick one up.

Are you coming to Redbones? Want me to get you one?

-- 

Andrew L. Duane (JOT-7)			duane@zk3.dec.com
Digital Equipment Corporation		(603)-884-1294
110 Spit Brook Road
M/S ZKO3-3/U14
Nashua, NH    03062-2698

Only my cat shares my opinions, and she's pretty clogged up with hair.