So I was coming back from dinner with my boys, turn onto the freeway, stab the throttle to merge, no problem, let off the throttle at about 60 and then my SES comes on and the truck is running rough. SES didn't bother me at first, cause it will with the predator programmer. I pulled off the freeway, came to a stop, and the truck was just lopeing bad. Valve cover harness? I checked the intercooler boots and they were all still attached. What gives? Oh, and the SES doesn't show up on my programmer. Also, I noticed that under the fuel system diagnostic menu there is a cut off description that reads "Manifold Gu" and the number fluctuates between 0.0 and 16,000 erractically! W Does anybody have a clue about that?
Thanks, Jeff

 

If the SES lit up, there's a code there. Too bad you're programmer isn't cooperating. No idea what a Manifold Gu is. The only manifold things that come to mind are MAP, MAT & MIAH.

From your description, I would say it's time to ohm the valve cover harness looking for either a loose connector or a failed injector solenoid. Do you know how to do the ohm test?

 

Yes I do, thanks to your response in another thread, and my intamate knowledge of Crown Forklifts! I read your reply in a different post, threw on the rain coat, moved the wifes camry out of the driveway and started my truck. No more SES and purring like a kitten! I believe your right, and I'll be checking it out in the morning. Thanks, Jeff

 

Diablo's programming is .....uhhhh..... not that good.
Try restoring to stock or just the tow/haul tune.

 

Hey Dan how are you? I have it on the tow/haul now, first problem I've ever had? If I had the money I would be all over Jodys' tunes, but my other bad habbit of archery gets me eveytime...... Has there been a lot of problems with them that I've missed?