Idle and acceleration issues -- 4kq

[Jpinkowish at aol.com]

Ben,
After you check all of the obvious stuff that others have pointed out(Bentley
gives you directions for testing the distributor Hall sensor), and your car
continues to die at random moments, you can be pretty sure that the ignition
control module(ICM) is on its way out.

Been there two months ago.  Car would work fine on some trips but die at
various times(at idle, at speed) during others.  At first the car would just
die instantly after shifting into neutral coming down a highway off ramp.  As
things worsened, there was some bucking during each engine cut out.

On the final trip, the car died every 2 miles for the final 10 miles.  Since
the fuel pump continued to run for about 2 sec after each engine shut down, I
reasoned that it wasn't the pump or its relay.  I also replaced both of the
fuel filters(they actually really needed replacing) without solving the shut
down problems.  Measured fuel pressure and current at the meter head and all
was fine.    The other big clue was a tach "bounce" when turning the ignition
switch to the "on" postition(not "crank").  However, the car just wouldn't
fail in the garage.

Finally I got a "no start" in the driveway.  Replaced the ICM, car started
right up.  Put the old ICM back in--no start.  Problem solved.

Replacing the ICM is a simple 1 hr job.  It's located behind the glovebox,
and Bentley tells you how to remove that.  Once you have the glovebox out,
you undo two screws and a clip to replace the ICM.   You can even test for a
while before reinstalling the box.

Part #  is 191 905 351B.  Get this from a yard.  This part is common to:
84-87 4kq
81-87 CGT
82-87 quattro coupe
81-88 5k(all)
80-83 5kt
88-90 80 4cyl
88-92 80/90 5cyl(all)
89-91 100


HTH

Jan Pinkowish
'85 4ksq
Bristol, CT