Hey guys, I've been running into some issues with my 05 6.0 with 115k on the clock. It's been running like hell as in misfiring since November, in and out of shops and dealerships with no one yet to fix it. Has good injectors, compression, fuel, hpop, new ficm, batteries, fuel, fuel pump, everything is as it should be. At any rpm once above idle it misfires, lurches, searches for gears, ect. I replaced the trans and torque converter, range selector the whole 9. The peculiar thing is that the starter shorts while cranking, clicking in cab fuzz box while driving and the trans gauge bottoms out while at operating temp once it starts missing. It will also freeze up my sct, and has no codes and then only 1 code for fuel in trans?? It sounds like the computer to me or the harness. Any help would be great since I'm thousands in the hole and not ever the dealerships can figure this out. Thanks guys

 

I'm definitely not a pro, but I'd be looking at a dead short in the engine harness or maybe even think about having the ECM/PCM reflashed, but it sounds like a hot wire grounding out to me, causing havoc on the electrical system. Have you pulled the main connector and checked the pins for being bent/ pushed back or corrosion? I'd probably start there myself. Check all your cables and connections make sure they're clean and tight.

 

If you haven't, I would unload the SCT for awhile and try that. Worth a shot, I have read about tuners causing problems.
Otherwise, I have seen 6.0's at my dealer on stands checking all wires/harnesses looking for similar electrical problems.

 

I really appreciate the feed back fellas, all my connections are good, I've personally searched high and low for shorts, loose grounds ect. Not saying that I couldn't have missed anything but the dealerships also haven't found anything alarming either. I have unloaded my tunes cleared dtcs and it still does it. The weird thing is is that sometimes it'll run flawlessly for up to weeks or run horrid like it is now with no sign of return. I really think the computer is toasted but I don't know of a way to test for that and I'm sick to death of tossing money at it honestly

 

I would post your questions in the 6.0 forum. Lots of experienced problems solvers down there too.

 

Thread moved to 6.0L Power Stroke Diesel forum.

Welcome to FTE and good luck finding the problem.

 

Check your alt for stray A/C voltage. Since it's intermittent I'd defiantly see about taking it to a good rebuild shop. The weird shifting was my first clue to the weird running condition.

 

Thanks, I'm new to this forum and didn't know there was a 6.0 one. I replaced the alt when I did the starter and nothing was out of the ordinary. I've had both dealerships and a garage chasing these wires and they haven't found anything which I find really odd

 

When my instrument cluster was bad I could get a condition like that, but only on restarts after the IC, radio, power windows went dead.

 

If all the peripherals are fine and check out healthy it's time to start to suspect that the ECU is bad. The ECU is the last thing to suspect because they're extremely reliable and rugged, but they can and do fail.

 

You need to wiggle test the harness
Start with the FICM harness

Your gauges and starter issue sound electrical that could raise hell on other electronics
This also points to harness

You need a DVM to check circuits
And a wire diagram
Try to do it when it acts up

 

Check for a short at the EBP: it grounds out VREF and everything goes whack-o after that...

 

He could back probe that connector to check VREF is 5V right?

 

Vref is 5v, if it's not, then there may be the issue.

 

I'd like to know a little bit more about the truck and what has been done to it? What mods, what brand are the replacement parts. What was done to "check" the harnesses, which grounds were checked? Are you using OEM filters for fuel and oil? Are you monitoring the truck's PIDs or just pulling codes? It seems like a lot of times the problem arises from simple things that are overlooked or assumed by others to be done.