Hey fellas, I got a good one for you, hopefully some guru/expert here can clear the fog in my head and lead me to an answer...

I have this 98 3.4L 4WD since 99, but its been sitting for a few years. Had a no-start issue when I started getting it road worthy again, but resolved that with a park/neutral switch, drove it for a week, then it mysteriously stalled while driving, would idle, but die when given gas. Got it home, pulled the bed off (with the help from a friend) replaced the fuel pump, but still can't hear the pump come on when the key is 'On'. When I try and start it, it acts like it wants to run, then dies. You can hear the pump run after it dies for a couple seconds, then stops. When cranking, you can hear it start to run, starter stops, and then it sounds like its starving of fuel. We checked at the pump and its getting battery voltage when cranking, so the pump is good (it should be, its new).

So here is where I'm at... either its the Circuit Opening Relay (Fuel Pump Relay) or the ECM. I think its the COR because I don't think its keeping the pump running, even though you can hear it for a second. Maybe I just don't want it to be the ECM, I dunno... Any ideas? I've beaten my head against the wall for a good long while on this one...

I don't have an OBD reader, was told I could check codes without one, maybe someone can show me how to do that, but I'm not sure this will result in 'the answer'... If you do happen to find the answer, I'll buy you a beer or two at the local virtual bar, lol

Any comments are welcomed, have a wonderful day

 

Sure sounds like the COR.
You can find a cheap OBDII reader at most auto parts stores. We're talking $20.00 or so. Not bad at all. I thought there was a way to make the CE light flash to indicate the code, using the DLC 1 plug, the one on the fuse box in the engine compartment, and a jumper, like with the gen 1 trucks, but I can't find it now. I'll keep looking.

Looking at the circuit, it could be the EFI relay, EFI fuse, or the COR. AND the ECU, of course. I would put my money on the COR, though.

Good luck, and let us know what you find!
Pat☺

 

The pump isn't supposed to be running all the time the key is on, just all of the time the ECU thinks the motor is either cranking or running.

Could also be the AMM based on the general symptoms. I'd try to verify the fuel pump or fuel pump power supply daisy chain of relays with a fuel pressure test first, before trying to throw parts at it.