random stalling issue

[red_mr2]

Hi everyone, im reaching out to you guys because i am lost on what can cause a random stalling issue. i have a 2012 6.2 ford raptor that randomly stalls on me, it stalls as if i turned off the igniton. when it stalls i put it in park and turn it back on with no problems. sometimes the truck feels like its idling a bit rough and eventually it stall out. i have no codes present on it. i have done the fuel pump fuse relocation, i have checked the purge valve. if i do a live data check on the truck i get no codes and if im watching the tps reading when it stalls out, everything goes flat like if i turned off the truck from the ignition. somtimes while driving ill get this like hesitation as if i downshifted but when checking the scanner all the reading went flat for a slip second as if the truck was turned off and then they came back on as if nothing happened. throttle body has been replaced and so has the pcm. issues continued even after replacing these parts. any help is appriciated.

 

[castine917]

Have you checked the ignition switch, ignition to pcm connection, things like that?

 

[castine917]

I thought I had a bad pcm on a chevy and found a bad wire couple feet from the pcm.

 

[red_mr2]

Have you checked the ignition switch, ignition to pcm connection, things like that?

thanks for the reply. i have a b10f1 coming from the BCM but i dont think that would make the truck stall out. from my understading that code wont make the truck stall out. ive checked some wiring but not sure where to start for the most part. it does not help that this truck is a prior law enforcement vehicle so it had all sorts of wires cut and spliced.

 

[Gryphon313]

2012 here. I have the exact same issue. Been working through the same steps as you. It only happens to my truck in stop and go traffic and only after it has been running for 15-20 minutes first. (Heat soak?) Mine cuts out at the same exact spot everyday on my way home from work. Like clockwork…

Definitely like someone just turned the truck off at the key, although all the dash lights are still on. Starts right back up. No associated codes. Once it starts cutting out, it seems to want to cut out more. Low idle, bogging when I use the brakes or turn the steering wheel. Once I am back to speed, it is fine.

I’ve done the ignition switch, fuse 27, evap purge, and fuel pump driver module. It has brand new plugs, coils and wires. I’m starting to worry that it’s the torque converter, but the way it cuts out has me thinking ignition/fuel.

Keep posting updates here because this seems to be a common theme.

Brad

 

[Gryphon313]

…And just like that, when I was parking in the garage at work this morning, I was able to get it to start to stall by pumping the brakes hard a couple times. It compensated and jumped the rpm’s up over 1000 and then settled down.

Brake booster. Has to be a vacuum leak due to a failing brake booster. Stop and go traffic. Low idle. On and off the brakes. No codes. The clues all fit.

**edit to add**

There is a check valve/sensor on the booster housing that I will rule out first.

 

[red_mr2]

2012 here. I have the exact same issue. Been working through the same steps as you. It only happens to my truck in stop and go traffic and only after it has been running for 15-20 minutes first. (Heat soak?) Mine cuts out at the same exact spot everyday on my way home from work. Like clockwork…

Definitely like someone just turned the truck off at the key, although all the dash lights are still on. Starts right back up. No associated codes. Once it starts cutting out, it seems to want to cut out more. Low idle, bogging when I use the brakes or turn the steering wheel. Once I am back to speed, it is fine.

I’ve done the ignition switch, fuse 27, evap purge, and fuel pump driver module. It has brand new plugs, coils and wires. I’m starting to worry that it’s the torque converter, but the way it cuts out has me thinking ignition/fuel.

Keep posting updates here because this seems to be a common theme.

Brad

i cant replicate my issue like clock work but it does do it more often after its been running for a while. i work and commute locally so its hard for me to get it to replicate the issue all the time; sometimes it wont do it all day. funny thing is that mine did the same thing today in the morning, i got to the gym put it in park, it idled like it was about to die, and the rpms shot up to 1000rpms and then came right back down. i was thinking fuel as well like if the fuel pump is cutting out randomly, but it does not feel like its running out of gas when its stalls out. hmmm ima have to pump my brakes a few times at idle to see if it does that. but if i leave the truck running in the driveway without pressing any brakes or anything it will stall on its own regardless. Ive take the truck to the dealership and they said they were not able to get it to stall out and they could not figure out the issue. i will keep posting here but please keep me updated on your situation too. im curious to see if we have the same isseue.

 

[Gryphon313]

I went out and pumped the brakes up with the truck off and it built pressure and held it. Started the truck with the brake pedal still pressed and it slowly pressed to the floor. Seems at first glance that the brake booster is good. There are multiple vacuum lines/check valves tied into the check valve on the booster, so I will start checking all of those.

And like yours, mine will stall at idle in park in the driveway with no other input.

 

[Gryphon313]

I have also been suspicious of the electronic throttle body. Specifically whatever part is responsible for idle air control. Honestly, I think if I could bump the idle up to say 750 rpm that might solve the issue. If I am able to keep the rpm’s up in the stop and go traffic, it will not stall. It was bad enough one day that I had to brake with my left foot while keeping the rpm’s up slightly with my right as I inches forward in traffic. That got the tranny temps up quickly though.

 

[pat247]

This definately sounds like a vacuum leak to me. Disconnect one side of the PCV hose on the passenger side and see if it changes anything. About a month ago I took the cup to my oil catch can off to empty it and while it was off I forgot and took the Raptor for a drive. Within a short distance my truck started to idle funky while sitting at a stop light. Remembered the cup was off so I drove home and put it back on and all good again.