[urq] I'm SO close to giving up...

[j.koenig]

Hi, John.

I'm stuck on the idea that the problem occurs at WOT, and that screams 
throttle switch to me.  The WOT switch triggers an open-loop, fixed duty 
cycle.  All other things being equal, it provides a richer mixture at full 
throttle.  If, however, the closed-loop duty cycle is already compensating 
for less than ideal mixture control, etc., etc., you can find yourself in a 
situation where going to closed-loop at WOT means moving the duty cycle in 
the wrong direction and going lean.

I may be full of crap, but it wasn't clear to me that you've completely 
ruled this out, and I've observed this and messed with it on  my own car. 
So, I hope maybe this helps!

John


----- Original Message ----- 
From: "Chaplen, John" <John.Chaplen at mercer.com>
Subject: [urq] I'm SO close to giving up...Anyone have a stick of TNT !!


Ok....basic problem...Under "WOT" and boost the car stumbles...back off
the throttle just a TAD and car starts pulling strong again...

What's been done...(not necessarily in this order)

1 New fuel injectors - all lines checked and cleaned
2 fuel Dist checked, but rebuild anyways (with increased flow) - all
retested..seems no problem with flow.
3 Volume test done - Ok'd
4 Pressure test done - Ok'd
5 Back flow from Exhaust - NP there
6 Checked for the small filter ...no problem there
7 checked WOT and IDLE switch..all fine there
8 new cap, rotor, spark plugs and wires...
9 Volt at coil is 13-14 volts
10 all grounds clean and tested
11 Compression check + - 10psi between all 5 cyl
12 Pulled all 5 plugs, they all look fine, no damage, they all look the
same too...clean and right color...(bosch tri-electrodes)
13 Swapped ECU with known good one...still same problem
14 checked Waste gate for torn diaphragm - no problem there
15 New fuel filters (twice)
16 Boost is NOT passing 14 psi (chipped by SJM)
17 checked all hoses and removed them, they are fine.
18 I have backed boost down to less than 9psi still same symptoms
19 removed full throttle cable (thinking it might be a full throttle
mode) nope..
20 new and checked the Freq valve for duty cycle looks correct and can
hear it working
21 rebuilt alternator to make sure voltage/amps were not a problem
21 car passes DEQ SUPER clean...

I guess my last question would be that I can think of, are there any
sensors that might be bad that would put the car into a reduced timing
mode?

I have had Scott Mockery drive the car, and it's NOT a fuel cut out
issue (4K cut out).

I just installed a fuel air meter box Wednesday, but have not had a
chance to run it...but from tests at idle with running WOT switch, it is
fully enriching as it should do...
and running and idle it's stoich? (sp)...I will be trying to drive it
this weekend to see if it's running too lean...But to me at this point I
feel like it's a timing issue?

(NOTE- I have done all of the above to try to fix this problem)

Any help would be so much appreciated!!!



John Chaplen CNE
Mercer Human Resource Consulting
Portland, OR 97204-3693





_______________________________________________
Audifans urq mailing list
Send posts to: mailto:urq at audifans.com
Manage your list connection: http://www.audifans.com/mailman/listinfo/urq
Have an urq question?  Check the Audifans Knowledgebase!
http://www.audi-quattro.org/cgi-bin/twiki/view/Audi/UrQuattro
Have an urq answer? ... Please help others by adding to the KB ... all 
contributions welcome!