still engine malfunction
Henry A Harper III
hah at alumni.rice.edu
Sat Aug 10 13:19:54 EDT 2002
If the chips are stock, on the other hand, it could be that the air mass
sensor has gone bad - I seem to recall another lister's car ran *quite*
poorly in "limp-home" mode with a bad air mass sensor. Look for the Bosch
part number on the sensor and try to get one from a Bosch dealer, much
cheaper than the Audi dealer network here in the US. Maybe try to swap with
a buddy's known good one first?
The computer can make fairly good guesses without the air mass sensor on
cold start and idle and closed-loop operation once the O2 sensor has warmed
up, but if you try to go to boosted mode (which is open loop) it has no
idea how much air is entering the engine. If it doesn't know how much air
is going in, it doesn't know how much fuel to put in either. The car isn't
going to run well.
The normal procedure when multiple codes are thrown is to work to fix the
first one indicated, because that might be causing some other codes that
are not real. Which was the first code indicated, was it the air mass
http://www.henry-harper.com hah at alumni.rice.edu
1991 200 quattro, 116k
1988 GTI 16v, 230k
On Saturday, August 10, 2002 4:51 AM, Mihnea Cotet
[SMTP:mik at info.fundp.ac.be] wrote:
> As for the "O2 sensor limit exceeded" and the "air mass sensor problem"
> fault codes, they usually happen when there is a vacuum/boost leak i.e. a
> torn hose or an Intercooler endcap that has a hole in it... BTDT...
> And the check engine light might be caused by the chip upgrade you have
> your ECU....
> Reply to me off-list and tell me where your chips do come from, this
> usually happens when the wrong chip is in the ECU...
> At 12:34 10/08/2002 +0200, =?iso-8859-2?Q?Endr=F5di_G=E1bor?= wrote:
> >Hi there,
> >So Unfortunatelly my car still does not want to run properly. As I
> >said before the cold start is terrible, it does not want to raise the
> >rpm when I push the gas pedal for seconds the first period ofthe
> >acceleration is good, but lately it starts to hesitating. Nowdays
> >sometimes the If I push the pedal the engine wants to stop, some
> >backfire comes up and after releasing it starts to run on higher rpm. -
> >Under normal cruise -with continous running- the check engine light
> >comes up, and when I relase the pedal it become dark again. I got 6
> >fault codes, /reference sendor problem, timing sensor problem ,hall
> >problem, air mass sensor problem, O sensor limit exceeded, and another
> >Interesting, when the engine is cold, and the air mass sensor plug is
> >not connected the engine starts well.
> >Has anybody idea what the hell is going in my car??
> >I've been to an Injector specialist who Checked all electrical parts
> >controlled by ECU and everything worked correctly.
> >Thanks Gabo
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> >200q20v at audifans.com
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