[V8] Loss of Power, Surging, Just Bad Behavior in Cold Weather

[Coleman, David]

I think I'll jump into this as well, as it seems there was a secret year-end V8 meeting that owners weren't aware of.  I ran my '91 V8 about 120 miles in the nasty pouring slush mess up along I-95 (DC to Wilm. DE) yesterday morning.  The rain was falling pretty hard, and passing trucks was practically blind.  After about 65 miles, the car started running on half power (or, perhaps, half the motor).  I chugged along in the slow lane for a while, mostly out of the way of the road spray, and the motor began to sort out and run normally -- for several miles.  Then it really started going haywire (probably what Ingo was referring to when he suggested the TPS plug).  The tach jumped around with an unintelligible reaction to throttle input.

It really only ran at all if I gave it 1/4 throttle or less, and got progressively difficult to modulate.  The tach would dive and lunge like crazy, and even when it would sit at zero (maybe 5 seconds at a time), the idiot lights stayed OFF.  They only came on once, when the car eventually died a mile from my house.  Five minutes passed, some Audi god blinked, and I got it restarted and coaxed it home, with the car bucking MADLY -- I'm surprised the drive shaft didn't get ejected.

I was disappointed, but thankful that the thing got me home.  Not sure if it was clutch disc, but in the garage w/ the hood open there was a distinct unfamiliar aroma.  Still lingers a bit there this morning.  Anyway, I'm effectively ruling out fuel delivery issues, considering the tach movement and the "almost start" sputter after releasing the key during attemps to restart.

I haven't pulled the codes yet, and the caps and rotors are about 1.5 years old.  Most everything else is very recently replaced (O2 and other sensors).  The car started and ran this morning, but with a sporadic hiccup, so I left it home.   I'm sure I wouldn't have wanted to be a delicate sensor or plug in that driving rain, so I'm hopeful the TPS plug is the sole culprit.  I wonder if wrapping it in plastic would help...

I'll report back w/ code output and "tps report".

-DaveC.
'91 V8 5M



> -----Original Message-----
> From: Torrence Thomas [mailto:tethomas at onlineaccesscards.com]
> Sent: Monday, December 15, 2003 10:02 AM
> To: v8 at audifans.com
> Subject: [V8] Loss of Power, Surging, Just Bad Behavior in 
> Cold Weather
> 
> 
> Hello All,
> 
> Just about the same time the cold hit our area here in Maryland, I 
> experienced the same exact problem of almost complete loss of 
> power while 
> driving, idling or anytime it feels like it should materialize. Never 
> happened before.
> 
> After logging to e-mail the following morning, I was surprised to see 
> others where having the same symptoms.
> Correct me if I'm wrong, but with misfiring (I can feel and 
> hear that as 
> well) shouldn't this be a distro (cap & rotors) problem?
> I too thought it was fuel starvation.
> 
> Reason being, as long as I have the throttle pretty wide 
> open, it runs with 
> an occasional hiccup. Nothing like accellerating to 100 MPH 
> to keep the car 
> running. Not good when snow and ice is present, even though I 
> drove out in 
> yesterdays early snow storm. Couldn't help smiling when the 
> Lexus LS400 
> couldn't keep the car straight on a simple incline and here I have a 
> possessed engine that wants to race. Finally I blew past him 
> with no loss 
> of control or anything. Gotta love the power of the rings.
> 
> Anyway, if the others experiencing the same problem have one thing in 
> common, ie unchanged distro & rotors, please say aye, aye.
> 
> If that's is true, I'm changing mine out and will advise if 
> it cured mine.
> 
> TIA
> 
> Torrence Thomas
> 90 V8 
> 
> _______________________________________________
> V8 mailing list
> V8 at audifans.com
> http://www.audifans.com/mailman/listinfo/v8
>