I have 1994 6.5 auto crewcab dually 4X4 with 290K,
Last week I lost the lift pump 140 miles away from home. After trouble shooting the pump with several heavy blows with screwdriver I got to NAPA and installed a new LP and Filter. I drove another 280 miles and after fueling up the truck just died getting on the interstate. It restarted immediately and promptly died under load and restarted. I had no issues the next 340 miles (760 miles in one day).After returning the truck has this shutdown/no restart issue every few miles.

Since the truck usually sits in the yard killing the grass. I have ignored the check engine light that flashes on until the truck is good and warm and returns sometimes under load. Today I got out the diagnostic paperclip and came up with 35,36 codes (41,76,78, were stored but don't seam related). My research indicates I cooked the PMD. I've had the truck for years and the PMD is still mounted to the pump. Before I lay down hard cash on parts I need some advice on any other possible causes.

Is one PMD as good as the next? OEM or aftermarket? Relocating the PMD to the intake manifold, firewall, or interior of the truck. Whats best? As long as I'm messing around what other mods make sense to improve mileage/performance? I just recently installed a superheavy duty transmission so the drive-train should be ready for extra power. Any input would be appreciated.

 

Go to a mechanical pump..... problems solved

 

PMD is a PMD, the flight systems built ones seem to be a little more HD than the others.. but I don't remember the name they're sold under. relocate it to behind the grill or anywhere it will get airflow and stay cool.

don't downgrade to the mechanical pump......

 

Mechanical with timing advance and reliable what more could you want