Running less smoothly after car is warm???

[Huw Powell]

> >I am driving a 1989 100 Quattro.  When I first start my car and take off it
> >goes smoothly up through all five gears with no hesitation.  However, often
> >after this it can be very hesitant and seems to get bogged down.  It would
> >seem to me that it is more normal for a car to run better after it has been
> >run a bit rather than when it is first started.  Any ideas as to why my car
> >is acting this way and what could be checked to get it to run smoothly
> >throughout?  Thanks in advance for any ideas.

One possibility is that the combustion chambers are all sooted up,
leading to some detonation, which then results in retarded timing.

Whne cold this wouldn't happen, and it would probably be more likely on
hot days, especially when taking off after a 5-10 minute shutdown, that
sort of thing.

A few runs with injector cleaner could help; so might some variation on
the "Italian tune-up" - one that seemed to work well with my 90, since
it is hard to actually run it wide open for long without running out of
road, was a few longish (1-2 hours) highway hauls at 80 or so - this was
enough to heat the oil up to about 120 C or so, which means things got
nice and hot and probably burned the some of the crap out of the
chambers (valve, head, piston surfaces).

Brett also mentioned the OXS, I would add that most of the "tune up"
parts should at least be checked for age/operability.

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/