86 5kcsq still stumbling when cold
kentmclean at mindspring.com
Tue Oct 4 20:06:05 EDT 2005
> Car starts fine, after about 30-45 seconds, the car will stumble
> and sometimes (usually) backfires slightly when taking off, it
> smoothes out once the car is moving and above about 2k rpms, once
> the car reaches about 80% of warmed up (which on this car, is the
> about 3mm to the left of center of the temp gauge) the problem
> pretty much goes away.
> What has been checked so far...
> Replaced crank case breather, replaced warm up regulator with a
> known good used one, checked for vaccum leaks at all the normal
> places on the MC1 (hoses at back of intake, between intake and
> head, turbo boots etc), new plugs, new airfilter, ...
O2 sensor? It wouldn't do much until after you start the car,
then it might be cantankerous until it warms up. ISV - it may
just need a good cleaning. The MFTS (multi-function temp. sensor)
is also problematic - a frequent source of failure that causes
funky problems. A Google search of the Audifans website will
tell you more.
Have you checked the DTC troubleshooting codes?
'94 100 S Avant, "Moody"
'89 200 TQ, "Bad Puppy" up in smoke
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