Hey guys, the other day while driving the check engine light came on, the motor immediately start running extremely rough and loss of power. I checked the under valve cover wiring harness and it had burnt pins, so I changed out the gasket with the harness in it. I thought this would resolve the issue but the check engine light is still on and the motor still runs like crap. The only thing is for the first second or two it's runs normal then reverts to the check engine light and running bad. Help!

 

What were the condition of the outer plugs in? If the inner harnesses were bad, the outer ones may also be in rough shape. Also were the valve cover gaskets the Dorman brand?

 

The harness connector had a melted pin in it. By the way, I had new glow plugs installed last winter. I put in a new Dorman gasket and inner valve cover wiring harness. Even with that the check engine light is still on and running like hell. I wonder if something is causing the harness to melt and that is keeping the CEL on

 

You'll need the codes, but Dorman GP/inj wiring products, including the gaskets, have a.... er.... checkered reputation.

 

Sounds like the IDM is shutting down one side. IDM could be bad.

 

Was that melted plug/pigtail replaced? If so, were the wires soldered or were crimp on connecters used? Soldering the wires is a must. Some have reported that the Doorman wiring stuff is bad out of the box. That said, I used a Doorman gasket for quite a while with no problems. Most recommend using Motorcraft or IH gaskets and harnesses. The IDM will shut down one bank I it detects a fault to protect itself, and a melted harness can cause a fault if bad enough. If Motorcraft/Beru glow plugs were not used when they were replaced they may be bad already.

 

Try to get your codes, when this has happened to me I never got a check engine light?

 

I had a CEL when I burnt my pins and when my IDM went bad