07 6.0 starts and immediately dies

[webb06]

Will start and run 1-2 seconds, if that, and immediately dies like key is shut off. Will restart and immediately die. Found a post on another forum about a pcm/tcm issue causing similar symptoms so I unplugged trans harness and started engine with starter jumper wire and engine will stay running. Ran it over 30 minutes idling today. Plug trans harness back into pcm and stalls within seconds. Swapped pcm with another. No change. Unplugged trans main connector on trans case and reconnected at pcm. Will idle all day. Swapped ficm as well because voltage did occasionally drop below 40v. No change. Anybody ever dealt with this? I can’t imagine anything inside the trans causing any issue like this…help

 

[6.0 Tech]

Try unplugging the fan and see if it stays running. It does seem like it’s something in the trans though, do you have something to monitor pids with? Almost wonder if your lock up solenoid is weak or something and being over powered, and the converter is locking at ifle

 

[webb06]

Ya we tried unplugging fan. No change. Have IDS

 

[DEEZUZ]

Hold throttle on start.

Remember that 6.4 I had... Maybe, maybe it's a tps issue.

 

[6.0 Tech]

Also, is the maf plugged in? There is one strategy that requires it to run. Had a similar one, thought it was an aftermarket alarm issue. We had test fit a compound kit in it, and I half ass threw it back together to just drive it out of the shop, and it wouldn’t run more than 5-10 seconds. Eventually we sold it, so I had to figure it out, as it ran when we brought it in the shop, pulled the alarm, no change, then boss told me to quit wasting time? Threw it all the way together, and ran no problem. I had still had the air box out while testing stuff, and lo and behold had to have the maf plugged in

 

[webb06]

This one will run without maf plugged in. What’s strange is the warmer it seems to get the less it wants to act up. We let it idle with trans unplugged for awhile and then tried again with trans connected and it would actually stay running. Throttle it up hard and after coming back down to idle it will die though.

 

[YODA]

I hate to say this, but carefully watch your dash oil pressure gauge the instant it starts. If the oil pressure drops the truck will shut down. The gauge is watching the normal truck oil pressure. If it is going to zero either that pump had failed or more likely the high pressure pump that drives the injectors has failed. Either way its an expensive fix. One other thing is during the repair the will be messing with the wiring harness the runs over the top of the engine. Be very careful not to damage that harness as it is no longer available.

 

[DEEZUZ]

 

[6.0 Tech]

What’s fuel pressure?

 

[webb06]

Honestly haven’t checked. It seems like it’s gotta be something electrical. Because if the trans harness is unplugged it will fire and run. We have also swapped ipr valve.

 

[bismic]

Have you scanned for codes?
Sounds like an issue with the Transmission Range Sensor. One failure mode of that sensor is that it can drag down the PCM power (voltage) - similar to what a fan clutch short can do.

 

[bismic]

Also, you could check to see if the reverse lights come on with the key in the run position and the transmission shifter moved to reverse.

 

[webb06]

I do know that it has the same symptoms in neutral as it does park. Can’t say I’ve actually look at range position data yet.

 

[bismic]

Any updates?

 

[webb06]

Haven’t pulled the truck back in the shop yet. Maybe this coming week

 

[Whiteshadow86]

I have this same exact problem. Truck revs too the moon just fine. If you hold throttle at 1000 rpm it doesn't skip a beat. Anything below it, shuts off. New hpop, pickup tube's, ipr, icp, ficim holds at 47.5 -48v. We went as far as taking out the branch tubes and checking them. They were fine. Also did blue spring kit. I'm at a loss

 

[webb06]

Got this truck back in the shop today and got it figured out. After watching sync and ficm sync I noticed that when it would die ficm sync would change to “no” right before it shut off. Also had code p2914 setting consistently which is Camshaft Position Output Circuit/Open. I should also note that this truck is an absolute rusted out rot box. So once I got a good look at the cam sensor I had a good feeling I was on the right track. I could tell the sensor had quite a bit of rust around it so I removed the sensor then got the power steering pump positioned out of the way. Once I got a good look at the block mounting surface I could tell that rust jacking had pushed the sensor far enough away from the camshaft that it wasn’t able to get a good signal. I took a small hammer and knocked the rust off the block mounting surface and put the sensor back in. But the sensor mounting surface was also deformed enough that it still wouldn’t stay running. Replaced sensor with new ford part and it immediately fired up and stayed running. Put it all back together and took it for a drive. Runs perfect. This truck also only has 52k miles but is in such terrible condition because of the rust everywhere. I hope this helps someone else that could be dealing with this.

 

[bismic]

Thanks for posting the conclusion. Rust jacking of that sensor is a known issue. Pulling codes helps eliminate guessing, but I will say that pulling the CMP gets for a visual inspection is sometimes helpful.

IMO - the key is pulling codes and observing/logging the SYNC value!