[V8] V8 stall downhill in gear

[Ed Kellock]

The fact of the matter is the engine cannot stall in the traditional
sense because as long as it is still engaged to the driveline, the
engine will still be turning.

We need an accurate description of "stall" in this case.  What
evidence makes you believe that the engine has stalled?  Do you have
warning lights on the dash?

Ed

----- Original Message ----- 
From: "Buchholz, Steven" <Steven.Buchholz at kla-tencor.com>
To: <v8 at audifans.com>
Sent: Tuesday, January 04, 2005 6:11 PM
Subject: RE: [V8] V8 stall downhill in gear


... there must be something here I'm not understanding ... how can an
engine on a manual transmission car stall when the car is in gear and
running at speed???

I think I know what you are talking about ... if you are coasting down
a
hill and decide to depress the clutch pedal with the throttle released
the engine dies ... is that it?  I've had similar experiences on my
cars.  I never fully tracked the problem down, but I'm pretty sure the
problem was due to water in the TPS.  Now that things are wet here
I've
noticed that #344 is having an issue where it behaves as if the
throttle
were fully released ... a total loss of power ... especially under WOT
acceleration.  I'm thinking that the ECU is seeing the idle switch
closing ... but I haven't confirmed this as yet ... someone else
pointed
out a good indicator if this might be happening ... set the trip
computer display to instantaneous MPG ... check to see if it is
showing
"---" when the engine dies.

The other possible culprit is the ISV ... if it is sticky it may cause
the engine to die on quick drops to idle.

Steve B
San Jose, CA (USA)

BTW, the V8 has EFI, so there is no need for the bypass valve that the
older CIS cars used ... the computer has full control of fuel and
stops
fuel from going to the engine by keeping the injectors closed ... this
is what the "---" on the trip computer display is telling you ... you
are effectively getting infinite fuel economy ... there's a good long
hill near where I live, I like to coast down the hill in gear with the
throttle at idle ... my daughter often asks me if we are not using any
gas as we make the descent.
>
> I've been having a problem for some time now with my
> V8 5spd Stalling while traveling downhill in gear
> without throttle.  If I let the throttle off for a
> certain period of time, the car will stall almost
> every time.  It will then start right up with no
> problems.  Car doesn't stall when coasting in neutral
> or while on throttle.  Aside from this stalling
> problem, car runs like a champ. Any ideas?  The TPS is
> not very old and seems to be positioned correctly.
> All vacuum hoses seem to be OK.  Any other ideas?  Any
> help would be greatly appreciated.  Thanks.
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