I've got a 97 318 auto Dakota sport extended cab that will not start consistently. When the problem first started, it would idle rough and I had to pump the gas pedal to keep it running.
That's when I thought it as a fuel pump issue so it tested the pressure at the fuel rail and it was at 50 psi and did not leak down so I figured the fuel pump was good.
Then I noticed when the key was in the on position, the fuel pump would continuously run. I also noticed that the fuel gauge would not work.
Ive checked the grounds, electrical connections, relays and battery.
Ive also got an ODBII reader and it shows no codes.
Today I was able to cycle the key on and off until the fuel gauge read and it started right up. I let it run for 20 minutes and it was perfect. Also when the fuel gauge reads, the fuel pump does what's its supposed to do, run a few seconds and stop.
Now I tried to start it and even if I can get the fuel gauge and pump to work properly, it won't start.

I love this truck and am not ready to give up on her.
What am I missing?
Thanks

 

first culprit would be PCM, as it controls the fuel sender and fuel pump relay.

 

Agrees. But first I’d check crank and cam sensors. If one or both are hitting sporadically it will do that. Are you getting spark? If you can’t get the engine going, I know a guy with a new 5.2, with it bored 30 over and a mid radical cam in it. Only thing reused in building the engine itself was the block. It’s ran 45 minutes, but not a foot. 😊

 

Thanks for the feedback.
I tested the Camshaft and Crankshaft sensors and they both are functioning.
I suspect the PCM but since the fuel pump is noticeably louder than it has been, I am going to replace it before I jump to the PCM. I should get it replaced this weekend and will update the thread.

Also, If it is the PCM, can it be repaired, buy one from Pull a part, buy online?

 

If you have good fuel pressure, and the pump runs the way it is supposed to, the pump isn't your problem.

Test and see what's missing. Do you have spark? Do you have good fuel pressure still? Are you getting injector pulse?

 

Well I replaced the fuel pump and it still won't start. Looks like it is the PCM. I tested the signal to the coil from the PCM and it flashes a few times and stops when cranking.

I will be pulling a pcm from a pull a part and giving that a shot.

There is a 99 dakota and darango with a 5.2 automatic 2 wheel drive at the local pull apart. Will this even pcm work in a 97 dakota 5.2 auto, 2 wheel drive?

 

Either should get you in a ballpark at least, give or take security programming

 

I replaced the PCM and it fixed the fuel pump continually running, no gauges issue.
Now it starts consistently but stalls after five seconds.
Sprayed starter fluid in throttle body and was able to keep it running a few more seconds making me think it was a fuel issue.
Pulled and cleaned throttle body, fuel rail and injectors.
cleaned and tested injectors, replaced IAC because it was very dirty.
tested fuel pressure and it was 45psi.
Also checked ASD relay. Entergizes when key in run for a few seconds. Entergizes when in start and returned to run position.

What could be keeping it from running?
If bad camshaft sensor, would it even start?
If bad crankshaft sensor wouldn't it trip the ASD? ASD stays entergized.

Im at my wits end......

 

Is it exactly 5 seconds every time? Does the fuel pump/coil lose power exactly then?

If so, you have a security (gray key) PCM.

 

Thanks! I hope that's it. It does seem to be a consisten 4-5 seconds every time.
How does the PCM send a kill signal? It must not go through the ASD relay because that stays entergized.

Maybe the fuel pump relay?