Stalling

[Tanzanite3]

Last week Lesley came home and mentioned that the Vette stalled on her 3 or 4 times in the village in traffic as she slowed to a stop with the clutch in. I took it for a drive and it was A-ok. However, these things don't fix themselves and guess what? Today the car was doing it again only this time I was driving. Exactly as Les described... put the clutch in just before stopping and ZERO revs. Stalled. Starts right up again but unless you keep the revs up it stalls again (but not all the time! That's the frustrating part!) Sometimes when you restart, seems if when the key has been completely removed from the ignition and replaced that it sometimes works ok. Anybody with a similar situation and know the cause. I'm gonna start lookin in the service manual to see if it can shed any light. Any help will be much appreciated.

 

[DDLS3]

Any shop with a code reader should be able to pin point the bad actor. It is likely to be one of the sensor devices.

Dale

 

[Ken]

Tanz, when mine started acting up like that, I cleaned the throttle body mouth and blades, and adjusted the TPS and IAC. It ran fine after that.

Ken

 

[Tanzanite3]

Maybe????

I was reading in the service manual and it mentioned that the ECM has to do some "relearning" of small driveability items if the battery has been disconnected. Idle speed is one of them!
I smell a rat here. Last weekend the switch for the rear hatch broke. I didn't realize that the interior lights were on when we came home. They weren't on when I thought about the switch breaking and went out to fix it either. The battery was dead as a doornail!! Probably 12 to 20 hours since we parked it after the drive! I disconnected the positive lead and recharged the battery.. took a long time! Reconnected the battery and all seemed ok. It was the next morning when things weren't going too smoothly for Lesley and two days after when it acted up on me. I would not be surprised if it were this relearning thing.
I checked for any codes and the only ones which come out are 12's .. lots of 'em. I quit counting after 8 in a row! So, I don't think there are any codes stored in there. They're reset when the battery is disconnected for a short time. Heck, ours was dead as dirt for many hours! So, if there were any, they've been reset. No new ones have been stored. Time and patience??

 

[ArtZR1991]

I might have some help. Went through this with my LT5, and you have made several comments that jive with what I found out. The battery disconnect does indeed cause the engine to have to re learn, but until then, it sets to default readings that do not stall the car. Assuming it did not suddenly get dirty or out of adjustment, as already mentioned, the more likely scenario is that the IAC motor has become mis calibrated (spark or voltage surge when reconnecting the battery, for example). In an obscure place in the phone book sized service manual for the LT5, a recalibration procedure is described. I think you will find it sounds familiar to one of the scenarios you describe in your car.

The procedure is to depress the pedal enough that ehen the engine runs, it is off idle, say 1500 rpm. DO NOT move your foot. Kill the engine by removing the key, reinsert, and start, allow to run for 10 seconds. Turn off, remove foot, remove key, wait 5 seconds and restart. The IAC is supposed to recalibrate itself.

The stalling is caused because the IAC is cutting off the idle air, and this calibration will cure it (assuming it is the same for your engine as an LT5 (probably is, since it is a software feature, and i would assume they would be consistent).

Hope this helps.

 

[ArtZR1991]

Any Luck?

 

[Tanzanite3]

Not 100% Sure

Art
I did all that you mentioned and have not had a chance to try it out yet because of the rainy weather. Don't take the Vette out if it's raining. But, if we're out and it starts to rain, that's different and OK cause I don't control that part!! Just spend another 5 or 6 hours cleaning!! Thanks to the weather controller (whoever he or she may be!!)
However, last time we did have the car out and just before you suggested the procedure, I had been idling the car with an elevated idle speed until it warmed up. Shut it off to come in for something and returned.. I think that I may have inadvertently performed almost the same procedure! The car ran well the last time out .. about 4 days ago! However, I have followed your suggestion to the letter and will let y'all (that's suthern 'marican) know the result next time we've had her out for a decent spin!

Thanks Art

P.S. That Ford of yours looks very nice and mean. To say nothing about the ZR1!! Great pic!

 

[ArtZR1991]

"whoever he or she may be?"

Us married guys can spot each other a mile away.


Seriously, if that does not work, I will pull the book out and look under your engine (both in same book) to see if there is something else.