Dodge Ram 2500 Pickup, 5.9L, EFI, 110" wheelbase, regular cab.
A little while back (maybe a month or so) my truck began refusing to start. It would crank and act like it had spark (halfway firing once or twice} then stop trying. I checked the fuel pressure and it had none. I assumed it was the fuel pump since I had been through this a couple years before and replacing the pump assembly solved the problem, at that time. This time it solved it again, for about a day. I made it to a neighboring city where it decided to stop running just as I was turning into a parking lot. I had installed a tee in the fuel line with a valve on it some time back to facilitate a project I was then working on and decided to use it to see if the fuel pump was still pumping. It was not.
Eventually, I got the truck home and started troubleshooting. I found that I was unable to force the pump to run from under the hood, at the fuel pump and ASD relays even though the relays had passed their tests. This seemed to say to me that there was a problem with the connector at the fuel pump assembly. I played with the connector, tightened up the barrels, added a dab of dielectric grease and ensured the weather packing was as it should be. The truck started and ran like a champ … until I got to town again. I parked, went in and did my shopping and came back out. The truck started, but before I could get out of the parking lot, it died. I crawled under and played with the connector some more. But, this time it wouldn’t start. I figured the plug was somehow at fault so after I towed the truck home once again, I ventured to our local U-Pull-it and snagged me a different connector, came home, cut the old one off and soldered the ‘new’ one in place and sealed up all the joints nice and snug. Once again the truck started and ran. This time I decided not to drive it off my property until it earned my trust. I used it around the house here pulling a trailer around behind it to do some end of summer seasonal chores and low and behold, it quit starting again. This time when I crawled under and played with the connector. All I did was unplug it and plug it back in. It started. I moved the truck to my work space and parked it. I started the thing once in a while just in passing as I was doing things. It started twice more then quit again. I unplugged and replugged it, it wouldn’t start. I tightened up the barrels on the pins again and now it still won’t start.
My question is, is there a condition that can be encountered wherein the ECU might set up a persistent (as in, carrying across attempts to start) no-start condition … maybe … (as in sometimes, but not all the time) that would be reset by unplugging the fuel pump connecter, allowing the pump to behave as intended once the connector is plugged back in?