re. 1989 Audi 200 QT - Hard Start Need Help 2nd Edition
Swann, Benjamin R. (BSWANN)
BSWANN at arinc.com
Thu Aug 23 13:39:10 EDT 2001
[Thanks for all of the suggestions. Looks the the strong consensus is that
I need to replace the fuel injectors.
I did replace the metal tipped fuel injectors with Viton tipped injectors
about 40,000 miles ago. Kinda hoping that I would get more mileage out of
the injectors. Also hoping that the local "german car specialist" would
have tested this since his invoice says he tested the fuel injection system.
Not sure whats involved in performing this test but probably way over my
In the mean time I have disconnected the Cold Start Valve on the theory that
if the injectors are leaking I already have too much fuel. Car seems to
start slightly better this morning. Please let me know if you think this is
a bad idea.
Once again thanks for all the help
I thought the condition was actually caused by a lean condition upon
cool-cold startup, when a rich mixture is required more. The injectors have
essentially leaked down the pressure out of the lines, just when you need it
most. It takes a few cranks whereby throttle plate is lifted slightly and
the lines are rechared adequately enough to provide a properly atomised
spray, and Vroom!
Where the fuel goes when leaked out I can only guess..some has probably
condensed on the cold manifold walls, while the rest has probably leaked out
into the atmosphere.
I don't think disabling the cold start injector will help, and will in fact
hurt on cool/cold mornings.
It does seem like 40K on your viton tipped injectors is not very good. You
can verify weepage by pulling the injectors, inserting fuse in FP
relay/ignition on, and lifting the throttle plate and observing the the tip
over time after a spray. Then it can be observed that fuel is slowly leaking
out around the where the tip is fastened to the injector and weeping up the
outside - not necessarily dripping. Easier said than done, but you have to
pull the injectors to replace anyway.
It is possible you have a bleed down somewhere else, possibly inside the
fuel distributor, or warmup regulator, in which case your mechanic did not
necessarily check everything out thouroughly. In any case, new injectors
and O-rings will provide you a starting point in that you know they have
been ruled out. Hopefully it will be that simple, if not, we'll all go for
Round II of more extensive trouble-shooting and diagnostics.
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