Hello folks. I'm new here and I'm vexed by a problem with my truck misfiring under load and uphills. I've researched this topic and it seems there are dozens of opinions and elusive results. I'm hoping Someone here can relate accurately to this problem.
I've heard "cops " are bad, plugs are sensitive, vacuum from the brakes need cleaned....etc.. It's obviously a common problem , but the solution is elusive.
The only error code I had was the VSS was bad. and insufficient flow through the egr. I replaced the EGR & it was smother, but not the problem It still has insufficient error. I replaced the motor speed sensor and for a week it ran like a charm, only to return to the same problem. It feels like a misfire and I smell poor combustion in the exhaust. I did not replace the Vss on the tranny, but just the one on the differential. Any suggestions on the misfire and the EGR would be greatly appreciated! Cheers...
One more thing it runs better when downshifting and raising the rpms.

 

i'm not a hi-tech man but i would check out the plug wires.with greater under hood heat and higher voltage going through the wires they seem to break down more offen,just an idea,good luck

 

Thanks for the reply. From what I gather I probably fried a cop by pressure washing the engine. It seem Tritons are prone to water problems. If not it is coincidental. I had a VSS error and a insufficient egr flow too , I replaced the EGR and MSS in the differential it ran great for a week....and came back so I'm replacing the dpfe, and like you said I strongly suspect the COPS being corrupted with water. Pressure washing a Triton is a no-no apparently. I'll post my results.

 

You didn't metion how many miles on truck. Mine had over 100 thousand on the plugs original platinums. Started a miss ocassionally under load. Changed the plugs and cured the problem.

 

My F250 with V10 had the same prob. After the engine got wet it would miss. The prob was the insulating cover that covers the COP to the plug. Over time they develop cracks and when moisture gets in the plug well I would get the miss. It did not set the MIL light( check engine). After it dryed up the miss went away. It would take up to 3 weeks to go away. I also had a prob with not ideling properly which set the MIL on . It was the small hose that goes from the PCV valve to the intake manfold. The last problem I had was a bad EGR ( stuck open) and a bed DPFE sensor.