DTCS 17535, 17537...long term fuel trim rich on my A4...

[Kris Hansen]

Hey Rob,

Have you removed power from the ECU to clear it of any
previous learning? Might be worth a shot..

Kris

--- Rob Andrews <randrews at sbcglobal.net> wrote:
> If anyone of you guys has ideas...I'd love to hear
> em...
> Below are copies of email between myself and another
> Audi tech friend....
>
>
> Ok ....here is the latest in my diagnostic.
> Bank 1 and 2 still going to -25%
> I looked at block 001 and 004 for coolant temp to
> see if that was going
> crazy but the reading seemed fine.  There are no
> pinched fuel hoses that I
> can see and I looked from the tank to the rail.  I
> pinched off the purge
> valve and that made no difference.  Swapped FPR and
> MAF, cleaned thottle
> body, changed plugs (which seemed to help for a
> little while...went to -21%
> and then rich to -25% after a day)
> What am I missing?  I'm about to jump from a cliff!
>
> Pinched off the valve (tried both sides, but only 1
> at a time) and it made
> no difference.
> I did just swap my plugs and I will drive the car
> tomorrow to see if that
> helps. The old ones looked tired. I'll get undeneath
> to check for fuel hose
> crimps tomorrow, and swap another MAF with an A6
> that is known to be good to
> see if it helps. I'll report back once I have these
> findings.
> So far...
> Still stumped :(
>
> > -----Original Message-----
> >
> > Sent: Tuesday, December 31, 2002 4:52 AM
> > To: rob at robsaudiworld.com
> > Subject: Re: Hey Mike...
> >
> >
> > Early 99 probably don,t have 211.
> > The purge valve is on the right hand side of
> engine bay on
> > top of air
> > cleaner assembly.
> >
> > ----- Original Message -----
> > From: "Rob Andrews" <randrews at sbcglobal.net>
> > To:
> > Sent: Monday, December 30, 2002 11:51 PM
> > Subject: RE:
> >
> > > Thanks!
> > > But where the heck if the fuel tank purge valve?
> > > Measuring block 211? That seems pretty high. I
> have an
> > early 99 model
> > > (i.e. the first of 99s to make it over here)
> > > The light only comes only when cruising. My fuel
> trim is
> > -25 and -23.4%
> > for
> > > bank 1 and bank 2...pretty darn rich. It only
> takes a few
> > minutes of
> > > driving to get it that way as well.
> > > o2 sensors seem to be fluctuating enough, from
> around .1 to
> > almost .9
> > volts
> > > and the heaters look to be working.
> > > I'm going to try one more MAF tomorrow in hopes
> that may
> > cure it...but I
> > > don't hold my breath...
> > > I'll poke around bentley somewhere and play with
> the car tomorrow.
> > > As always...your help is gratefully appreciated.
> > >
> > >
> > > > -----Original Message-----
> > > > From: mike hadley
> > > > Sent: Monday, December 30, 2002 6:51 PM
> > > > To: rob at robsaudiworld.com
> > > > Subject: Re:
> > > >
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "Rob Andrews" <randrews at sbcglobal.net>
> > > > To: "'
> > > > Sent: Sunday, December 29, 2002 10:10 PM
> > > > Subject: RE:
> > > >
> > > >
> > > > >
> > > > > Well I hate to bug you again, but I figured
> I could use
> > > > your expertise.
> > > > > My 99 A4 2.8Q is throwing DTCs 17535 and
> 17537...long term
> > > > fuel trim rich
> > > > > for bank 1 and bank 2.
> > > > > I tested the MAF, and swapped with another
> friends,
> > swapped the FPR,
> > > > tested
> > > > > the 02 sensors with Vag-com and meter and
> they seem to be
> > > > within spec.
> > > > > Any other ideas what could cause such a
> problem?
> > > > >
> > > > > Rob
> > > > >
> > > > I take it with a known good mass meter it
> still came on?
> > > > I guess the 1rst thing would be to pinch of
> the fuel tank
> > > > purge valve to
> > > > make sure it is not sucking fuel vapors when
> it is not
> > supposed to.
> > > > make sure the fuel return hose did not get
> pinched
> > under the car (
> > > > sometimes damaged on lifts or jacks) which
> will raise
> > fuel pressure.
> > > > With the Vag com look at measureing block 211
> in Engine.
> > > > See if it shows
> > > > Maf grams per seconds. There should be a
> specified and actual
> > > > amount. Drive
> > > > the car under load and watch numbers, they
> should stay
> > > > close.( does not work
> > > > on all 99 and earlier cars)
> > > > Also does the light come on at idle or when
> cruising?
> > > > Let me know.
> > > > P.S. if it cures the problem when pinching off
> the purge
> > > > valve it may be
> > > > the valve or a saturated charcoal canister (
> if you like to
> > > > squeeze every
> > > > bit of gas when filling.
> > > >
> > > >
> > > >
>
----------------------------------------------------------------
> Rob Andrews
> 99 A4 2.8QS   83 Ur-Q
> www.robsaudiworld.com
> Visit my new web page!
>


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