OK a little background on my truck I have an 06 f150 with the 5.4, it has longtube headers with high flow resonators, a ram air intake and jet power flo high flow mass air sensor. I was driving home and when I gave it gas coming out of a turn the engine just shut off and then it gave one good backfire. It had no shuttering or sign of misfire prior to this and the computer threw trouble codes p0351,p0352,p0353,p0354,p0355,p0356,p0357,p0358. I took this as something caused all 8 coil packs circuits a and b to fail at once and i have no idea what to do about it. I also checked all the connectors at the ECM and it doesn't appear to be from a bad connection.

 

Check your motor mounts and transmission mount. When you gassed it comming out of the turn (left hander I'd bet) the motor could have shifted and pinched some wires. That would be my guess.

I had that happen many years ago, took forever to figure it out.

 

Does it run now?

 

I haven't had a chance to check the motor mounts specifically but when i checked the area for any melted wires from my new headers i didn't even see any in the general area. and now it just acts like it has no spark at all so i'm thinking it will most likely end up being the ECM.

 

Are you using a programmer with custom tunes?

 

have the diablo sport predator programmer on it with their 87 octane performance tune but thats it

 

Lets add it all up.....

Diablo 87 CANNED performance tune+JLT ram air intake+JET POS MAF+Lontubes with no cats=Your truck is probably running lean and you puckered your plugs or something else in the ignition system but that's just my opinion.......

 

well when it died it didn't shutter or misfire at first like you would expect with pucker the plugs or if all the coils where going out so i'm leaning towards a wiring problem because i also tried restoring the stock tune into the ecm and that didn't help. I think next I'm gonna pull one spark plug and test the coil against a brand new one to see if there is a voltage difference and if somebody knows where i can find a wiring diagram for the ignition system that would be a huge help. Thanks

 

shouldnt the misfires be P030x codes? am i missing something here?

 

no your not the misfire never happened but if the coil packs were going out i would think it would have involved some misfiring even if it was only momentary but instead when the truck shut off it was as if i just turned the key off and until I find a wiring diagram I'm not a hundred percent sure about the wiring from the ECM to the coils but i think its individual sets of wiring from the ECM to each coil rather than one wire going to a common distribution point so that kinda rules out the harness failing to all cylinders at once. putting me at replacing the ECM.

 

I did a little bit more research.....some of those codes can be from a "fail safe mode" event.....and a fsm can be triggered by a dirty throttle body and/or a fouled maf....

Just speculating that's all

 

My engine quit without warning, went to failsafe, had to wait about 5 minutes before it would restart. It was a dirty throttlebody.

 

well i just changed the maf and that didn't do anything and the throttle body appeared clean but i sprayed it down with TB cleaner and it didn't help with the problem but thanks for the idea

 

What's your battery voltage at?

 

The common connection for all the coils would be the ground, wouldn't it? If you lost your ground it might have the same effect, I would think. But I'm still guessing.