[urq] I'm SO close to giving up - Part 2?

Tue Apr 19 13:07:35 EDT 2005

Yup, sounds similar to my problem. Does it happen in every gear? Mine pulled
well in 1-3 but in 4th or 5th, my effective redline went down to somewhere
around 5K in 4th and 4K in 5th, under boost. And got worse as time passed.
It was clearly a fuel issue. I too installed a little apex-i A/F meter for
that reason. IIRC, my car never went over 0.8V, and dropped off more when
(or due to) the stumble occurred.

Not sure that cleaning out the tank actually cured the problem of the car
leaning out at high load, but it certainly moved the redlines back up
higher. My tank had an inch of gunge in the bottom, and when I drained it,
the feed hose dripped while the return hose gushed. Another symptom that the
tank was clogged was that the pump started making funny noises, not just the
usual occasional crackling. It went into high pitched mode.

The tank cleaning cost 70$ I think. It's probably something most of us
should do on our ancient Audis anyways. Since they're inside the car, they
won't rust from the outside like on most other cars. On most cars the tanks
are likely rusted through long before they have the time to get this plugged
up. So, I guess we're "lucky."

Hope this helps.

Cheers, Brady
-------------

-----Original Message-----
From: Louis-Alain_Richard at computerhorizons.com
[mailto:Louis-Alain_Richard at computerhorizons.com]
Sent: April 19, 2005 10:59 AM
To: quattrodude at comcast.net; bradym at sympatico.ca
Cc: a.sigal at bluewin.ch; 'Chaplen, John'; 'Urq List'
Subject: RE: [urq] I'm SO close to giving up - Part 2?

In my book, a fuel pump is a fuel pump... meaning if it works, then it
works correctly. I don't think they go weaker, they just quit.

But your symptoms are reminding me of similar on Brady's car. Leaning out
at high revs. If it were spark, you'd see rich condition. So must be fuel.

If I am right, Brady's solution was to remove the fuel tank and clear the
crud at the bottom of it; then he had it recoated with a rustproof stuff.

Brady? Can you help John avout this?

LaR

             "JP Chaplen"
             <quattrodude at comc
             ast.net>                                                   To
             Sent by:                  <a.sigal at bluewin.ch>
             urq-bounces at audif                                          cc
             ans.com                   'Urq List' <urq at audifans.com>,
                                       "'Chaplen, John'"
                                       <John.Chaplen at mercer.com>
             2005-04-19 02:58                                      Subject
                                       RE: [urq] I'm SO close to giving up
                                       - Part 2?

Ok here is what I found from the Air/Fuel meter...say at 4th gear..at 3K
rpms...stomp on it..WOT...boost comes up...13psi..Accel good, fuel
rich...but then starts to lean out at about 4500 and in the red by
5500...

Last thing I can think of swapping is fuel pump at this point?

Another $150 bucks...anyone think anything else before I sink another
$150 into it?

-----Original Message-----
From: urq-bounces+quattrodude=comcast.net at audifans.com
[mailto:urq-bounces+quattrodude=comcast.net at audifans.com] On Behalf Of
Ado Sigal
Sent: Monday, April 18, 2005 7:01 PM
Cc: Urq List; Chaplen, John
Subject: Re: [urq] I'm SO close to giving up

Two things should be also mentioned. First you should establish what is
missing at WOT, the fuel or the spark. Spark can be easily checked by
wiring the flash gun and running it through deliberately miss aligned
bonnet, and taping it on the windscreen. That would take you on the
right track.
Second thing to check is the WOT switch operation. On two occasions I
found on my ex GV engines, that the switch would close correctly at 3/4
throttle, but would open again at close to WOT. After bending the leaver

slightly, the symptoms similar to yours disappeared.

HTH,

Ado

>
>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
>
>
>
>
>