> Subject: [gti-vr6] Cold start stumble/stall/high idle ?
> From: MKranz <mkranz@mindspring<img src=/i/dc.gif border=0 width=35 height=15>>
> Date: Mon, 17 Aug 1998 22:47:56 -0400
> All this talk of hot start problems has got me thinking about my cold
> start problems.
> My '97 (born 4/97) does not like to start when:
> 1) it's the first start of the morning, and
> 2) the air temp is above ~65°F.
> When I start it, the revs jump to 1300, then falls off to a near-stall,
> about 300-500 revs. At such low RPMs, the engine coughs and sputters and
> generally complains for several seconds. Then it recovers to a high and
> unstable idle (900 RPM).
> I always thought it was a problem with my ECU, but in order for the
> dealer to diagnose it, I would have to have left the car overnight, and
> I can't part with my baby for that long!
That sure sounds like the classic AA ECU cold-start / rough idle
problem. FWIW, my car is also a 4/97 with the AA ECU, but has only had
this problem once or twice when it's been sitting in the garage for
undriven for several days.
> About two weeks ago, I replaced my stock chip with a Garrett chip.
> (Note: WOW!) The stumble is still there. So, logically, the problem is
> not in the computer, right?
Wrong. The standard Garrett AA chip is based on (or at least it claims
to be on the 1551's readout) version 01. VW's fix for the ECU is to
install a newer software version; V02 or V03 depending on who you
ask.... Garrett is aware of this version's existance; if I were you I'd
ask him if he couldn't make you up a chip based on that version.
> So what else can I check? Someone suggested
> checking the security of the Mass Airflow sensor -- where is this thing,
It's the tube goes back from your airbox towards the throttle body that
has some wires plugged into it...
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