[s-cars] I'm broke but my car is filthy rich

[Darin Nederhoff]

Gents,

After many years of reliable service my full RS2'd UrS4 has starting
driving me slightly insane.  Last year it developed an issue with a
high boost cut out problem which seemed very much like a weak coil.
After MUCH tail chasing it came down to the one year old Bosch fuel
pump being a bit too wimpy (the prior OEM Pierburg had worked
beautifully up until the day it suddenly died).  Anyhow, the pump was
replaced with the 034 Motorsports high flow unit and relay and the
problem went away... until a few days ago.

Now it is a bit like deja vu.  Car is once again sporadically running
super rich at idle and under boost.  It sort of stumbles at idle and
stinks up the neighborhood with fumes and smoke.  Example:
http://www.youtube.com/watch?v=rkmTC2_RRj8&feature=g-upl

Coils/boots, plugs, O2 sensor, bypass valve, intake hose and fuel pump
all done last fall.  I also tried swapping MAFs and carefully cleaning
my RS2 MAF last fall as well.  No change.  Tested over and over for
boost leaks and could find anything.

I've been averaging 20.7 MPG in mixed city/highway driving although I
suspect that as of the last few days it is far worse.

Anyone else ever dealt with this sort of thing?  Kind of scratching my
head here as this car rarely stumps me.

One thing I DO notice is that it tends to act up more if it is
especially warm outside or hot & humid.  Could be coincidental....


-- 
Darin Nederhoff
Plymouth, MN

http://S-CARS.ORG/site