Need help diagnosing

***cleatus12r*** · #1 Tue, February 8th, 2011, 09:56 AM

No clue.

Bob · #2 Tue, February 8th, 2011, 11:41 AM

Thanks guys, Ha Ha Well started great warmed up and drove 30 miles no problems. Shut it off and let it sit for about 1/2 hour. Started, warmed up and drove 30 miles again no problems. It was -15 this morning. So I don't think it is a cold weather issue. I will keep the updates comming until we figure it out. Oh, I have not changed back to stock yet.

eabrust · #3 Tue, February 8th, 2011, 07:21 PM

Did you do remote FICM update, or pull it out/send in/reinstall it? If you removed/reinstalled, are the FICM connectors tight and clicked in?

And if it isn't a new FICM, perhaps check it for 48V, maybe it decided to poop out just after updating (that's how my luck typically is).

Just thinking...

good luck

Eric

Bob · #4 Tue, February 8th, 2011, 08:03 PM

Good point, I did the remote programming so a connection should not be a problem, but the chance that is going out is a good chance. If there was no bad luck I would have no luck at all.

Weent out later today and it did not bog down, but acted like it had a miss, real suttle. I just dont know why it is so random.

StripperDJ · #5 Tue, February 8th, 2011, 09:14 PM

sounds very weird...doesnt really sound like a injector issue to me.. Have you checked you fuel pressure ????? Normally the fuel pump doesnt go in and out like that,,,they just normally take a crap on you all at once,,,but im interested in knowing what it is. Keep me posted on this... It is so hard to diagnose one of these things without actually putting hands on it, but i will do my best to help...my email is brad@phptune.com Im outta town this week and i dont have my computer with me to check those emails but if need be send me a pm and with a number i can reach you at and i will give you a ring the first chance i get...... thanks,, and god bless

Bob · #6 Wed, February 9th, 2011, 10:27 PM

Thanks Brad. Today it has had that slight miss both times I started it and drove it. I changed it back to stock last night so it did not seem to make a difference yet. I am curious, how much oil should or could I expect to see in my inter cooler tubes. It seem a bit excessive to me. Could this be a factor? I checked the antifreeze and it was good. I will check the oil in the am when it is cold. FYI, I just changed the oil about a month ago and put the rev-x in it.

John Anderson · #7 Thu, February 10th, 2011, 09:50 PM

Definately check your fuel pressure. You are describing classic fuel pump going out problems. I have two 6.0's in the past couple of years that the pump start and stop working almost at random. The first one drove me nuts till I drove it for a week with the fuel pressure gauge hooked up.

When the fuel pump is taking a dump the trucks will idle perfectly, start great, and then randomly crap out once you get them under any load.