88 80Q, Runs rough upon starting //corrected verbiage!//

[Eric Huppert]

Changed control pressure actuator to differential pressure regulator. It's
late, I'm tired...

Eric

Gentlemen,

Have two perspective buyers coming to look at my sons car, and a "new"
problem has surfaced. (new to me, my 17 yo doesn't tell me these things
until he thinks of it, or I ask!)

If car is allowed to sit 5-10 minutes after shutting off, (or even on a cold
start) upon restart car fires, then starts to stumble and drop RPM's.
Feathering gas pedal, etc, doesn't help. But, discovered that full throttle
will get the rpm's up, but when let off it still runs rough. It clears up in
a minute or two, but something's not quite right

Troubleshooting to present:

Car is tuned up, no vacuum leaks, ISV functioning and clean. Not a fuel
leakdown issue (check valve), not the FP. (BTDT several times with other
Audis)

Ran codes. Initially no codes, but do get full throttle code when throttle
is fully opened.

	So, checked switch (both full and idle portion) according to Bentley.
Voltage specs are good, Ohm check works out for both switches.

Air plate clean and moves smoothly, etc. etc.

Then on to the differential pressure regulator. Following Bentley, getting
correct voltage to unit, but upon following procedure and checking for
10ma/100ma (utilizing digital meter) I only get the 10ma. Opening throttle
fully doesn't change anything (as it should per the manual)...

The Bentley is just tad vague... My interpretation of the Bentley DPR test
is "voltage is good, WOT switch has no effect, replace DPR! I'm also not
getting decent ma readings when car is running.

Thoughts, BTDT???? Sure this is a sensor issue of some sort and can, (and
will) be easily fixed. Need to resolve this quickly!

Cheers, Eric