Ok, 95 Dakota, 3.9 2wd, 160k Miles. My brother was driving it and it all of sudden died after driving for a while. Looked at and looked at it, didn't think it was getting fuel, hard to hear if fuel pump was turning on because he was on the highway with constant cars. All of a sudden, she starts up and runs great all the way home. So I took it for a 45 min. drive shutting it off once and then it died on me. It seemed to me the fuel pump wasn't turning on. It would turn on for a second but it still wouldn't start. So I towed it home and now we decided to get a fuel pump, I went to start it and it fired right up and I brought it into the garage. I found out that the fuel pump only turns on once until you try to start it. Instead of trying to turn the key on over and over without trying to start it. So maybe it was just doing that when I was checking it out on the road. Check engine light never game on. Any ideas?

 

sounds more like an ecm problem vs a fuel problem, perhaps a bad ground near the pump or the ecm.

 

Would a bad ground cause it to just shut off after driving for a while? Then just magically start back again.

 

yes it could, but i'm still leaning twoards a bad ecm or prom chip.

 

Ok, well I changed the fuel pump and it still shuts down after about 45 min. or so.

 

got your pm, i'm still leaning twoards ecm or prom chip. i had an issue similar to this on my blazer i replaced the map sensor, tpi sensor, fuel pump and all that still didn't fix the problem, so the last item was the ecm. ran fine after that.

 

Thanks, I'll head to the junkyard in a little bit.

 

Ok, well I put in a new ecm and it still shut's down after it get's warmed up. I checked all the wiring and didn't see anything. I'm running out of ideas.

 

Someone just suggested a coil. That it's getting too hot and causing it to fail. Possible?

 

It's a good possibility. When the coil gets hot the inside of the coil heats up and expands so if it's old and getting to hot, you're not runnning msd or mallory w/ a stock coil are you?