RE: s4 rough acceleration

["Martin, Gary G" <MartinGG@aetna.com>]

I don't run my car hard until it's fully warmed up. I guess my wording,
implied that. 
I'm new to the list, so thanks for the tips. Haven't had a chance to follow
up on them yet.
Funny thing is, I waxed the S4 today, and it seems to run better tonight!  I
have run thru about 
half a tank with BG 44K in it. Maybe dirty injectors? Took a quick look at
Bentley manual today	
and indicates throttle position sensor can cause rough acceleration. Any
thoughts?  I'll keep you posted. 
-----Original Message-----
From: rjandrew@post.cis.smu.edu [mailto:rjandrew@post.cis.smu.edu]
Sent: Wednesday, February 03, 1999 1:49 PM
To: Marc_Nguyen@mail.amsinc.com
Cc: quattro@coimbra.ans.net
Subject: Re: s4 rough acceleration


Ok....
I remember reading that you are NOT supposed to use full throttle
or exceed 4000RPM until oil temp is 80 degrees Celcius???
Correct? Wrong?
I also remember a thread (i'm not trying to start another one) about the 
pistons being oval until the motor warms up... Then it becomes round..
Or was it the bore that was oval... Oh well... Point being I don't 
think it is a good idea to get on the accelerator hard until the car
has fully warmed up... Then have FUN!!

HTH!
Rich Andrews
rjandrew@Post.cis.smu.edu
'86 4kq
> > I have a 94 s4, bought at 87k,nearing 100k now and seems to have
> developed a
> > roughness during acceleration. Most noticeable at 3000 to 4500 rpm at
> half to full
> > throttle in second gear. Less in 1st and 3rd. None in 4th and 5th. Idles
> fine, pulls
> > strong. More noticeable when cold. One shop couldn't find anything
wrong,
> another had a
> > computer read out of failing engine RPM sensor, which was replaced and
> seemed to improve
> > it somewhat.  Any suggestions?
> 
> A friend has a similar problem with his '92 S4.  If the car sits outside
> overnight and ambient temperature is below about 40 deg F, it "bucks"
under
> moderate to hard acceleration above 3000 rpm.  After about 10 minutes it
> runs fine.  If the overnight outside temp is warmer, it runs fine.  We
> dumped the error codes and found nothing.  Took it to the dealer and they
> couldn't figure it out either.  A local wrench has suggested
> testing/checking the coolant temperature sensor.  We'll be checking that
> this weekend.  I will post if it is the problem.
> 
> BTW, if you dump the error codes with the car off, you will always get the
> engine RPM sensor fault (2111, I think).  The Bentley says to ignore it.
> The dealer my friend took his car to did just that and replaced the
sensor.
> They did not charge him for it when we pointed out their mistake.  You
> might want to check with the shop and see if that's how they did it.
> 
> - Marc
> 
> '93 S4
> '85 urq
> 
> 
>