Hi everyone new here I just purchased an 05 F 250 Crew cab 4x4 150000 miles. Has 4in exhaust, EGR delete, AFE Breather, Head studs,. I was having a hot start issue so after reading post I changed out the Dummy Plugs. But now I have a issue with the Glow Plug Control Module shorting out. If I leave it unplugged at 55mph and high gear there is a bad shake in the motor like a miss or bad injector now any thoughts.

 

shorting out gpmc is not very common, how ever, with that said and the fact of leaving it unplugged makes a shake like a miss, it is very well possible that you have a wire in the harness touching something that it shouldnt. be it voltage or ground. these things can be a REAAAAAAAAAAAAALLLLLLLLL pain to find. I remember having to go open up the wire looms on a couple trucks and wiggle every wire every 2-3 inches until i found a Vref signal wire touching a ground wire for an unrelated circuit causing all kinds of driveability issues. Do you have a test light? I would load test the circuits and make sure theres no wires crossing paths or harness rubbed through... Also check the ground at the block. You would be amazed what a bad ground or missing ground can cause... Im talking about the one on the front of the block

 

I will check for the ground in the morning thanks

 

Do you know if the High Pressure Oil System Updates were done at time of h/g's? Cap Screws, Rail Plugs and Stand Pipes should all be updated! Sounds like an internal high pressure oil leak.

Dave

 

Okay I feel like a real dummy here I retraced my steps and started to tear it back down and got to the FICM and found one plug not plugged all the way in. What a headache.

Thanks for your suggestions it runs great again.