Coupe Quattro 20V Carbon Fouling Plugs

[Brett Fairbanks]

I can't seem to get my early build '90 Coupe Quattro project sorted so I can
drive it.  The car starts O.K. when cold, but doesn't want to idle.  I've
swapped in two other idle stabilizer valves, but they behave the same way.
It seems like the car is choking on fuel.  I've found fuel puddles in the
intake and in the rubber intake boot.  Checked spray patterns on the
injectors when I installed new fuel injector seals and all the injectors
were pulsing and spraying a decent pattern.  I've tried to clean up all the
vacuum leaks I could find.  Air intake is unrestricted.

 

The car will rev fine, but a little stumbly until it warms up.  Makes good
power underway, and the idle cleans up a little after it's hot.  Still, as
the plugs continue to foul, the idle situation degrades until the plugs have
to be replaced.  I have to put the pedal to the floor (flood clear mode) to
get the car to re-start when it's hot.

 

Any ideas?  I'm getting frustrated as I need to be able to get this car on
the road.  Anyone run into this on their 20 Valve in the past?  Any
suggestions are truly appreciated.

 

Thanks!

 

Brett Fairbanks

Delaware, Ohio