Ever had an AT vehicle stall for no reason?

[01rangerxl]

After going to a store on the other side of town (25 minute trip one way), my truck stalled as I was pulling into my driveway. It's the first time it has ever stalled, and was completely unexpected since it has an automatic. My driveway is a little steep, but not crazy. I pulled in like normal, hit the brakes (not hard, just like normal), and the truck just shuts off while still in drive. The radio was still playing, and the check engine and check gauge lights came on. I cranked the truck over and it started right up like nothing happened, and the check engine and check gauge lights went off. I plugged in a code reader and got no codes at all. Has anyone had something like this happen? I'm pretty much writing it off as a freak incident, as the truck seems to be running and driving fine, it just surprised me a lot.

 

[mechanicx]

Yes I have seen that happen. And there wasn't a trace of why it happened, and it usually didn't happen again.

 

[caprice_2nv]

It can happen for no reason at all. I've heard of more than one EFI automatic equipped vehicle stall the odd time for no reason at all without ever having a diagnose-able problem to be found and fixed.

 

[simple_gifts]

Maybe the LUTC didn't disengage quickly enough.

 

[440Magnum]

There's always a REASON ;-)

Yes, I've had fuel-injected AT vehicles stall. Most often its a dirty idle air control valve so that as you slow to a stop, the engine idle drops too low and it dies. I've also had a bad MAP sensor cause a stall on acceleration, and a bad cam position sensor cause a stall at random times.

I've also heard that some vehicles (particularly some GMs and front-drive Chryslers from the 80s) will stall because the transmission torque convertor lockup clutch failed to disengage, but I've never experienced that myself.

 

[Propflux01]

It can also come from the brake booster, Since it died when you hit eh brakes, the sudden need for vacuum leaned the mixture too much too fast for the ECM to adjust mixture. Sort of like some vehicles while running, you disconnect the PVC and it creates a huge vacuum leak causing the engine to stall.

 

[hypervish]

I agree with 440Magnum there is always a reason. Like he mentioned it is usually a dirty iacv, dirty maf sensor, or dirty throttle body.

 

[Colt45ws]

On Fords this is nearly always caused by a bad/dirty Idle air control valve. If it keeps occurring, take it off and clean it out, see if that fixes it.

 

[sciphi]

I had my Buick stall when the transmission was kicked into R accidentally. Then another time when I disconnected a vacuum line, ran the engine for a few minutes doing a water decarbonization, and reconnected it. The engine immediately stalled when that line was reconnected. Guess my feelings when that happened. It turned out fine, of course.

 

[StevieC]

Was it a clean stall like someone turned the key off or was it a dirty sputtering stall?

That would give us some insight.

 

[meep]

Originally Posted By: 440Magnum
There's always a REASON ;-)

Yes, I've had fuel-injected AT vehicles stall. Most often its a dirty idle air control valve so that as you slow to a stop, the engine idle drops too low and it dies. I've also had a bad MAP sensor cause a stall on acceleration, and a bad cam position sensor cause a stall at random times.

I've also heard that some vehicles (particularly some GMs and front-drive Chryslers from the 80s) will stall because the transmission torque convertor lockup clutch failed to disengage, but I've never experienced that myself.


^^^ yes

 

[bigmike]

The reason is explained rather well in the following thread:

https://bobistheoilguy.com/forums/threads/ghosts.136192/

 

[mechtech2]

Low on fuel? That is my first guess, if there are no real problems.

 

[JustinH]

Mine would stall when the torque converter clutch was burned up. This was a ford thunderbird with a beefed up e series van transmission.

 

[Steve S]

There is always a reason.

 

[01rangerxl]

It was like I just turned the key off. There was no sputtering or anything like that. One second it was on, the next it was off.

IAC and MAF were recently cleaned for preventive maintenance a few weeks ago. Idle has been completely normal, and cleaning the MAF and IAC didn't change performance or anything.

Tim H's brake booster suggestion seems to be the most likely suspect at this point. It did happen just after hitting the brakes.

All seems well now. No weird idle, no rough running, and no more stalling.

This truck did have another freak incident about 25K miles ago. I pulled into a parking spot and left the wheels turned. When I got back in the truck, the steering seemed bound up and it wouldn't move in gear. Check engine and check gauge lights came on. I shut it off, wiggled the wheel some, started it back up and everything was fine. It hasn't done that since. Again, even with the trouble lights on, it didn't store a code.

 

[StevieC]

Lights came on and it didn't store a code? Intermittent stalling with no sputtering?

Loose connection at the ECM, ECM is loosing power because of a defective ignition switch or the ECM is faulty.

It is possible for the accessories to stay on but the ECM loose power if the ignition switch is faulty.

 

[01rangerxl]

No codes at all.

Faulty ECM would be a suspect, except that it has no other problems to speak of. It did this once, completely out of the blue, and has been fine since.

The ignition switch could be a possibility. The chime that lets you know the key is in the ignition works when it wants to...it has been that way for at least 40K miles.

 

[01rangerxl]

Originally Posted By: bigmike
The reason is explained rather well in the following thread:

https://bobistheoilguy.com/forums/threads/ghosts.136192/



That could be it! Got to love Ford quirks. This truck has never failed to start or broken down, but it definitely has quirks. It does fun things like bouncing the speedometer around when completely stopped, and the OEM CD player would steal CDs for a period of days. Sometimes the radio would eject a CD a little bit, then snatch it back before I could grab it. And then once in a while it likes to put the fear of a major failure in you, only to seem as if nothing happened a few seconds later.

I guess it's payback for hitting the RPM limiter, hitting the speed limiter, brake stands, overloading, and taking it places 2WDs are not supposed to go.

 

[StevieC]

Originally Posted By: 01rangerxl
No codes at all.

Faulty ECM would be a suspect, except that it has no other problems to speak of. It did this once, completely out of the blue, and has been fine since.

The ignition switch could be a possibility. The chime that lets you know the key is in the ignition works when it wants to...it has been that way for at least 40K miles.
Now the facts come out...

Ignition switch is my bet.... Try driving it and rock the ignition switch back/forth enough to see if you can make it loose contact but not enough to shut off the engine by reaching the off position or the crank position.

It may only work after the vehicle has been running for a while because the ignition switch is warm inside and the metal contacts have expanded / contracted a bit because of the temperature change and it just needs slight jaring to set it off.

Good luck!