1-bad-z28

I can drive around for about an hour then it will start missing in the upper rpm's then slowly get worse to the point that I can barely do anything but idle. I can let it sit for awhile and cool off then it will run like a charm again. The only code i'm getting is low TP voltage. Any ideas?

Injuneer

Look for things that can break down due to excessive heat.... IC Module and Opti optical sensor come to mind. Plug wire insulation weakens as it heats up. Coil??

RedThunder1994

If the fuel pump is going bad then it will also do this once it heats up.

1-bad-z28

fuel pump is not that old...it is a walbro 255lph from racetronix. Plug wires are fine. Nothing physically wrong with coil. I was also thinking opti but I don't want to tell that to myself yet. That is already the third one i've had in 5 yrs. keep the replies coming and thanks for the replies already

Injuneer

Have you considered spacing the ICM out from the head to reduce heat soak?

How do you know there's nothing "physically" wrong with the coil? Not sure how you would know the internal insulation was breaking down due to heat.

And you're sure the plug wires are not losing their insulating value at high temps?

Have you noticed any posts on these forums about short-term failures of the Walbro pumps?

Seems like you are sort of blowing off the suggestions.

1-bad-z28

I replaced the ICM about 2 yrs ago. I spaced it then and not had any problems since.

I guess what I meant to say about the coil is there is nothing visually wrong with it. I will check into it a little more.

As for the wires, they are brand new and zip tied very good to keep them off the headers. I have since checked them and they are still good (no hard spots or burnt marks or arching).


No...I haven't. Worth looking into

I am not blowing off any suggestions. I am just giving more info to you guys to help me figure out the problem. I am looking into every suggestion. Thanks for the replies....keep them coming