Thanks for replying and trying to help. If you read the full thread, I've done all that already.

 

I have read the whole thread, I didnt see where you individually checked the cylinders. Im not saying to pull the plug wires individually to find a bad plug, Im not thinking a plug or wire is bad, theve been changed alot, it could help you isolate the problem down to just one cylinder. I also didnt see where you checked the fuel pressure. I could have missed that stuff though.

Edit: I saw the fuel pressure, 70psi...

 

My wife hates our house. Come visit, leave your truck here and we'll go to dinner. Come back hours later the house will mysteriously be burnt down along with your truck. With the history of the problems it'll be easy to blame it on your truck.


just saying.


I was thinking about your truck all the way to work (1 hour) this morning. Going through each troubleshooting step in my head. Boggles my mind.

 

He may have not mentioned it (I am not going through this thread ) but I can attest, he's checked it. The only thing we haven't done is logged it. But the afr is solid and changes as needed (commanded), no spikes in lean afr. Even when the throttle is slowly rolled to 60% (to keep lean spike out of picture) it still misses (but doesn't log the miss).

 

Holty, sent you four tunes to try out. I changed your misfire tables to be super sensitive over most areas. Looking at the scans it appears you go into this "misfire" right around 2800-3000 rpm. Just in the area where the misfire table is max'ed.

 

Is the fp at a base of 70? I've heard of some injectors not liking high pressures like that....try running a base of 50 and see what happens...

 

Any chances that it could be bad fuel?

 

I wanna say his base is 52-54#'s. But that could be different now since the Lonnie setup was installed.

I think he's been through a couple small fills spoolin.

 

Holty, have you checked the harness from the PCM to the coil clip? The big one that's part of the engine harness? I've read of wires in their cracking from heat and too much movement. If there's on that's broken yet still barely touching it might cause the coil to lose temporary signal. I'm just throwing out random ideas at this point.

 

As strange as it sounds, my boat, third time out this year, started doing the same thing around half throttle and under load. Come to find out I had water in the fuel, didnt do it the first or second time I ran it this year but third was the charm. Not sure if I got a bad fill up but I went back to check their fuel and didnt notice it in a clear container but caused a lot of headache...