I'm hoping some one can help me figure out why my 2500 keeps idling rough then shutting off. Sometimes it will restart right away sometimes it won't start for a long time. I changed fuel filter and cleaned pcm connections. It has an after market pcm located by the grill. Any thoughts. Thanks

 

Is the after market PCM in a place where it could get wet?

Can you tell if any of the wires are corroded? right behind the grill seems like an awful place for a sensitive computer. But I thought the 6.5s didnt have a whole lot of computer systems period.

How many miles?
What else aftermarket does the truck have?

 

The 6.5s have some issue with the pmd overheating so i installed a Dorman Injection Pump Driver with Relocation Kit, Chevy/GMC (1994-00) 6.5L Diesel, PMD, Resistor, Cooler, & 6' Harness. That's been there for over a year. I put behind grill which is the recommendation from them. I have a bigger exhaust but thats it. Truck started running rough about a 6 weeks ago. I added diesel fuel cleaner and drove it around a couple weeks. Nothing really changed. Then it started shuting off and losing power, especially on hills. I changed fuel filter and bled fuel line and got it to start. Seemed ok but the next morning it wouldn't start and has been sitting ever since.