6.5 stuttering

[sd9465]

I have a 94 K2500 W/ a 6.5TD and a 5-speed. Ihave owned the pickup for seven years and have done all the mechanic work myself. Right now the engine has a missing and stuttering problem. What bothers me is that it comes and goes. Starts great, doesn't smoke idling or driving. It has stalled occasionally, but that has quit now and just misses once in a while at idle and stutters badly while driving. Have checked for fuel pressure and filter has been changed. I think it is PMD, but wondering if anyone has any ideas before I change it. The pump and injectors only have about 15k on them. Pretty short lived Pmd as far as I am concerned.

[heathj]

Where did you check for fuel pressure at? I ran into the same problem on my 94 suburban. When I opened the valve by the thermostat while the truck was running, it would stall out. Come to find out, the lift pump was not running. If the truck runs while the valve is open and fuel pours out onto the ground, in theory the lift pump is working.

Unfortunately, I discovered that the PMD was bad as well. From my understanding, if the lift pump is supplying fuel, then it has to be the injector pump or the PMD. Since your pump is relatively new, and the PMD is the cheaper part to randomly change, I would probably start there.

Hey, by the way, I am new here. Anyone know how to set up the signature?

[sd9465]

I checked fuel pressure by putting in a gauge before the fuel bleeder upby the thermostat housing. I sometimes wonder about the oil pressure switch, because sometimes the factory gauge in the cab will fluctuate while driving, but it never gets below about 30 psi. If you shut the engine of cold You can hear the fuel pump run until the engine bleeds down the oil pressure. So I just don't think It is the lift pump, OPS, or a pressure problem.. Frustating as he..

[heathj]

Yeah, if you can get pressure at the thermostat, then the lift pump system (relay, OPS, and pump) should be functioning. I would open the valve while running to break the vacuum just to be sure. If it can run while the drain valve is open, then the motor is getting enough fuel. But, I'm going to say it is the PMD. If you can find the guy who designed it, I'll help you let the air out of his tires. Everyday. For the rest of his life.