Engine dies randomly!!?

[ice445]

Yep, same problem here.. I have a 2020 GT manual with less than 13K on it. Granted, I also have a supercharger, header, full exhaust (no cats), and a tune.. But hearing it happens with stock cars AND modified cars is concerning.

Anytime I'm at a low speed, my car will potentially do this. Shifts fine and seems to have plenty of power for what I've got in it. No problems at WOT. But as soon as I go to slow down, on occasion, the engine will start surging and then quickly just shut off. I wouldn't call it stalling like poor clutch technique, but the car just.. dies. Happens when I push the clutch in and get into neutral. Happens if I leave the car in gear and stop with the brakes+ clutch, it's not easily replicable because it almost seems random..

Also happens just in slow speed operation, like in a drive thru. If I'm sitting still and I need to pull up, I'll put the car into first, let out the clutch and give it a little gas to get rolling, and as soon as I push the clutch back in it's like the RPMs just go crazy. In that scenario, they'll usually instantly fluctuate upwards violently 700-1k+ rpms whatever I'm currently at, then they drop down to 700 and start bouncing up and down between 8-400, then car shuts off. Or sometimes the car just immediately shuts off after the violent increase in RPMs.

I'm thinking it has to be the tune or something fuel related, purge valve/evap, throttle body/tps, fuel pump? My mechanic just took apart the whole engine basically to install a new oil pump gear and he inspected all gaskets and hoses and didn't find any signs of a vacuum leak. We thought maybe turbulent air from the way the CAI is set up, but I've pretty much ruled that out since it happens when the car doesn't have enough force to be sucking up excess air. Also kinda thinking tune, but when we first got the supercharger installed we had it dyno tuned and it ran just fine for the tuner and my mechanic who drove it back to the shop.

Rarely get codes, whenever I do it's for a rich or lean code and usually only one bank.

Sounds like the VCT/cam timing is dropping out. Surprising it's not setting a code, but apparently it often won't if it doesn't last for long enough or if the car dies.

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[natepcbfl]

Sounds like the VCT/cam timing is dropping out. Surprising it's not setting a code, but apparently it often won't if it doesn't last for long enough or if the car dies.

I had an issue with my VCT solenoids and it NEVER threw a code. Others with the same issue, no code. So it seems that if it is the VCT solenoids you will most likely not have a code. Just throwing my 2 cents out there.

 

[cantseemtosleep]

Sounds like the VCT/cam timing is dropping out. Surprising it's not setting a code, but apparently it often won't if it doesn't last for long enough or if the car dies.

Hopefully not, but it's possible since others with similar symptoms found out this was causing it. It seems there's about 100 different things that can cause this combination of symptoms which is stupidly frustrating.

I had an issue with my VCT solenoids and it NEVER threw a code. Others with the same issue, no code. So it seems that if it is the VCT solenoids you will most likely not have a code. Just throwing my 2 cents out there.

Mine hasn't thrown a code *for* the VCT solenoids specifically, if that makes any difference. The code(s) it has thrown have always been for bank 1/2 system lean or system rich.

Does anyone know if I'd be able to diagnose faulty sensors/VCT with an HP Tuners datalogging tool? I'm not mechanically inclined enough to check them myself let alone exchange them. I know the cams can be controlled through the ECM so maybe it's possible the values are just not what they need to be for the tune I'm running?

 

[natepcbfl]

Hopefully not, but it's possible since others with similar symptoms found out this was causing it. It seems there's about 100 different things that can cause this combination of symptoms which is stupidly frustrating.




Mine hasn't thrown a code *for* the VCT solenoids specifically, if that makes any difference. The code(s) it has thrown have always been for bank 1/2 system lean or system rich.

Does anyone know if I'd be able to diagnose faulty sensors/VCT with an HP Tuners datalogging tool? I'm not mechanically inclined enough to check them myself let alone exchange them. I know the cams can be controlled through the ECM so maybe it's possible the values are just not what they need to be for the tune I'm running?

Just to clarify, no codes at all, nothing in memory and no CE light comes on. So if it's giving any code it might not be the VCT solenoids. Sorry if I wasn't clear enough on that.

Here is another thread about shitty idle and talk of the VCT solenoids
https://www.mustang6g.com/forums/threads/idle-goes-rough-randomly-stock-tune.133398/#post-2757177

 

[cantseemtosleep]

Just to clarify, no codes at all, nothing in memory and no CE light comes on. So if it's giving any code it might not be the VCT solenoids. Sorry if I wasn't clear enough on that.

Here is another thread about shitty idle and talk of the VCT solenoids
https://www.mustang6g.com/forums/threads/idle-goes-rough-randomly-stock-tune.133398/#post-2757177

Thanks for the clarification. Yeah, I saw that thread as well. It's odd that those having problems with the VCT weren't throwing codes cause there's a few codes that can be thrown when there's issues with the VCT solenoid/actuator. None of them relate to lean/rich codes, though. They're all over/under retardation of cams so maybe it's just a tuning issue. Guess I'll find out after I datalog and send it to the tuner.

 

[Trocki]

I know this is an old thread but this is a problem I ran into recently and seemed to be getting worse and worse. I saw several people mention it was a tune that fixed the issue for them but I uploaded an SCT X4 tune and it made no difference. Then I uploaded a second tune, this time changing my idle speed in the tune and it worked! No more issues at all! The key is the engine idle speed, for sure. Tune that, (I picked 825, I think) and you should be over this annoyingly difficult to troubleshoot issue.

 

[ice445]

I know this is an old thread but this is a problem I ran into recently and seemed to be getting worse and worse. I saw several people mention it was a tune that fixed the issue for them but I uploaded an SCT X4 tune and it made no difference. Then I uploaded a second tune, this time changing my idle speed in the tune and it worked! No more issues at all! The key is the engine idle speed, for sure. Tune that, (I picked 825, I think) and you should be over this annoyingly difficult to troubleshoot issue.

If bumping idle speed fixes it, its likely for sure a VCT issue.

 

[Trocki]

If bumping idle speed fixes it, its likely for sure a VCT issue.

Yeah, I spoke too soon. The idle speed tune did NOT fix the issue.

 

[Temovic55]

Sounds like the VCT/cam timing is dropping out. Surprising it's not setting a code, but apparently it often won't if it doesn't last for long enough or if the car dies.

Same thing with both banks P0172,175 and misfires P0300. Never had any of those problems of stalling when the car was bone stock. But asa I supercharged it! All that pain came into my world. I'm thinking tune related, vmp thinking TB. Sent few logs to other tuners to confirm it and we will decide later on.

 

[Darinbranham]

BUMP
facing this exact issue now in my 2020 did anyone solve this? only codes are for TB/ pedal position after it dies. I have replaced both of the sensors

 

[Deep pockets]

This happened again today and I am getting tired of it. I don't drive the car enough as it's a 2015 with just over 2K miles only. Coasting to a stop in neutral and I just hear the idle go low then dead. This seems to happen whether the car is hot or cold. I've experienced this about 5-6 times so far within the 2K miles. My first new Ford and most likely my last any Ford. Good thing it's not a daily driver. Anyone experiencing this have any success having the dealer reflash with TSB15-0128? I believe the TSB is for low idle or idle dip.

I too have had this happen same scenario no codes no loss of acceleration what does the TSB tell us needs to be done?

 

[Deep pockets]

I too have had this happen same scenario no codes no loss of acceleration what does the TSB tell us needs to be done?

Just got a code VCT sensor bank A took 4 months to show

 

[ryanking5.0]

Yes, this happened 2 times on my Lund tune, seems to happen more commonly with people who have the 10 speed. After a ton of trial and error and logs, Lund set my idle to 950RPM. It's much more stable now!

Hi, did you datalog the exact moment of stall and sent to Lund? I am going through this issue right now, but Lund keeps saying my tune is fine and they need the datalog of stalling moment.

 

[ryanking5.0]

I had the same issue after I tuned my car with Lund tune. After a revision it never happened again. Check your tune!!!

Hi, did you datalog the exact moment of stall and sent to Lund? I am going through this issue right now, but Lund keeps saying my tune is fine and they need the datalog of stalling moment.

 

[ryanking5.0]

Just an FYI, I have a 2015 and have not "yet" done the digital dash swap. I am sure the DD will see fluctuations much more than the analog needle. The thing you might notice first is just a dip in the RPM's after coming to a stop or while rolling to a stopping point but, in neutral. It did that for a while before it finally started stalling out.

I am going through same issue. Is your car manual or auto trans?

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