4K QUATTRO IDLE PROBLEM AFTER INJECTOR OVERHAUL

[Brady Moffatt]

This is a common one. Chances are
1) you have a slightly gummed up idle stabilizer valve (ISV). Remove it and
clean it with throttle body cleaner. Brake or carb cleaner also work,
2) Your ISV duty cycle is out of spec Adjust with the throttle bypass screw
on the side of the intake,
3) Your differential pressure regulator current is out of spec. Adjust with
3mm hex key on top of air flap assembly.

Of course this is assuming there are no vacuum leaks, and that everything is
in generally good working order. Just doing 2 and 3 can sometimes
miraculously cure an unstable idle.

For details on this, run, don't walk, to HUW's SITE OF AUDI OMNISCIENCE and
look under "tuning CIS-E."
http://www.humanspeakers.com/audi/index.html

Cheers,
Brady
Urq, 4kq, Z

-----Original Message-----
From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com]On
Behalf Of mark wolfson

I recently went to an independent shop in the area that flushed my
injectors, replaced two injectors and all injector seat seals. Car runs much
better, as one injector was squirting, not spraying. However, now, the car
idles low, and when the car is warmed up, when I let off the accelerator
(while driving), the idle dips to about 5-600rpm, which causes stumbling to
the point of almost stalling. Then it immediately spikes back up again to
normal (if you call it normal). Also, then at startup when car is warm, I
get full crank hard start, then it catches and dips again to almost stalling
level, then spikes back up to 800rpm, but runs a bit lumpy, low. I went back
to the repair shop. They looked at it, and stated that a vacum tube got soft
and buckled against something that cut off the air. So they took off the
rubber tube and put a spring in it to prevent it from collapsing. It seemed
to work for awhile, but that is not the problem. Before they found this, the
tech told me that since there was less air getting in the system because now
the injector seals were tighter, the idle might be lower. He said the idle
is self-adjusting. The car seems to start cold ok. What is the problem? I
would guess fuel pressure, but the car otherwise runs stronger now that the
injectors were cleaned/replaced. Any suggestions?
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