+1. And make sure it is a strong blue spark and not a weak yellow one.

And your fuel pressure is good. Was not aware that you just changed fuel pump.

 

Ok an update. Still need help. I have removed ECM and sprayed freeze spray all over it and could never get the truck to act up and not start.
I went ahead and replaced the crank sensor and the cps in the distributor. I was hoping it was fixed. The owner and decided it must have something to do with driving about 50 miles at 60 or 70 mph since that is what he does everyday. So I decided to drive it to my dads and give that theory a try. I drove it 100 miles last night and I did get a code half way to destination p0305 (cylinder 5 misfire). Shut it off for the night. Woke up this morning and sure enough it would not start. When it would crank but not start we checked the spark and it had good spark. Fuel pressure was a solid 53psi. Checked voltage at cylinder 1 injector and it was getting a signal from computer. Still no start. We checked compression and 125 psi. We poured gas in the intake and started cranking, it didn't start immediately but it did start on a few cylinders. I held the gas at half throttle and after about 6 seconds it cleared up and runs great now like it always does once you get it started.

 

Hhhmmm..... need to re-run your test, and plug a noid light into one of the injector connectors, and see if you are getting injector pulse. PCM controls the ground side of the circuit..... ASD relay supplies power.

 

When I said I checked voltage at injector I meant we used an analog volt meter and we watched it pulse.

 

Ah, ok. That's a good test.

So, either too much, or not enough gas. Given the description in your last post, sounds like too much gas. Might be a temp sensor, or leaky injector. Might try a bleed-down test on the fuel system.....

 

125 psi across the board or ??? Thats not very good, if you get a bunch of cyld with that low of number it will be a pita to start due to lack of comp. Do a comp test when the motor is cold see what numbers you get.

 

Ok I am thinking it's the ECM. I have been to multiple junk yards and out of 30 dodge 3.9's. not a single one still had the computer. I just called another local junk yard and they don't even give a warranty on their's. so it's possible that if you buy it and it doesn't work I'm out $200. I do not know what to do. I was trying to keep the bill affordable for my friend but right now it looks like my only option is through Auto Zone.

Does anyone happen to have a spare ECM that works or know where I can get one? It would even be nice to have one to just plug up to see if it fixes the problem before I spend the money.

 

Well i ordered a remanufactured ECM and installed it during the time that the truck would not start. After new ECM installed the truck did the exact same thing. It would not start. I am going to try to return the ECM. Hopefully i can get my money back. I just knew that this was going to fix it.

It still wont start so i tested resistance on coolant temp sensor and air intake sensor. Both read around 9,000 to 10,000 ohms.

I am stuck I don't know what to do.

 

The miss fire at #5 is telling me to suggest to you, to unscrew the precat o2. I'm not reading back in the thread right now to see if you have. But I'd try it for the heck of it. And the coil and coil wire new?

 

Yes all new wires, plugs, cap, rotor button, crank sensor, cam ignition sensor ( in the distributor), new fuel pump.

And do what with o2 sensor?