[s-cars] Starting/Running issues

[Mark Rivera]

Thanks, Chris.  I had an interesting drive at lunch:

I remember checking the codes when I first bought the car, and I just
checked them again at lunch.  Same one still stored in there:

2413 -- Mixture Adjustment, Adaptation limit exceeded, Symptom: Rich
mixture, increased fuel consumption.

Makes sense with the 14MPG I've gotten since I bought it 6 mos. ago.  I
replaced the O2 sensor last week, and have noticed a bit better fuel
mileage, but I haven't run a full tank through yet.

So, I pulled the 5amp fuse, waited, replaced it, and verified that no codes
existed (got the 4444 code).

Turned it off and started it up with a cleared ECU, and she idled pretty
rough for a while.  OK, the ECU must be relearning everything.  Started off
and accelerated moderately at about 5psi, and the engine did NOT want to rev
over about 3500.  I mean, it eventually did, but lots of bucking and slow
acceleration happened.  After a couple miles, things started to clear up.
Smooth acceleration, still some bucking/misfiring, and would you believe it,
I consistently saw 17-18 psi on the gauge a few times!  That's at least 2
psi over anything I've seen before!

I tried driving it at all rpms at all different loads, and I could tell the
ECU was still trying to tune.  It probably still has some tuning to do, but
I think things are looking up.

I hope all this sounds normal, and I'll keep you guys posted with a fuel
mileage and driveability report, once I get some more miles behind me...

Thanks!

Mark



-----Original Message-----
From: chris chambers [mailto:fastscirocco_2000 at yahoo.com]
Sent: Tuesday, May 01, 2007 09:44
To: Mark Rivera
Subject: Re: [s-cars] Starting/Running issues


Mark,

Have you checked to see if there are any codes yet?
I'm going to guess no, the link below explains how to
red the fault codes:

http://www.sjmautotechnik.com/trouble_shooting/ecuf20v.html

LEt us know what codes there are.

HTH
Chris


--- Mark Rivera <mrivera at webcats.net> wrote:

> My (unmodified) 93 S4 is still having some driveability issues.  With
> the
> engine cold, the car starts and idles fine, but any throttle
> application or
> load on the engine in the first minute or so results in the engine
> wanting
> to die.  It WILL rev fine if I coax it above about 2000 rpm or so.
> Seems to
> get a little bit worse when it's moist or wet outside.  I just
> replaced the
> O2 sensor, and though the fuel mileage is much improved, that didn't
> fix the
> problem.  My workaround is as follows:  Start the engine and
> immediately
> give a little bit of throttle and hold the revs at 2000-3000rpm.
> After
> about 25-30 seconds, the engine idles down about 500rpm, even though
> I don't
> move my throttle foot at all.  After that, I take off and drive
> normally,
> and everything is fine.  No hesitation upon takeoff anymore....
> Wonder what
> the faulty component is?
>
> Also, and this may or may not be related, between about 10psi and
> full boost
> (15-16psi) I get what feels like misfiring between about 3000-5000
> rpm.  One
> of the resons I installed the boost gauge was to rule out a boost
> control
> issue.  The boost level is rock solid.  Whatever level it goes to
> when I
> floor the pedal, it stays there.
>
> Are my ignition components starting to fail?  Does this explain both
> issues?
>
> Thanks a ton.  I have 4 of 5 1.8T coil packs in my garage, just
> waiting to
> be used for the conversion...
>
> Mark
> _______________________________________________
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> S-CAR-List at audifans.com
> http://www.audifans.com/mailman/listinfo/s-car-list
>


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