SpitFire

I have replaced the ignition coil, pick up coil, distributor, cap and rotor, plug wires.

The starter, plugs and battery are good.

I have not replaced the crank sensor or alternator.

Firstly when the issue started. I hit a pothole incredibly hard. Jeep sputtered a bit but continued to run for the next few days. I then had to cut of the Catalytic converter and run a straight pipe until I can buy a new Cat.

A few day after that is when I started having starting intermittent starting issues. I replaced the ignition coil, distributor, cap and rotor and plug wires. It started for a few minutes and died. Then I replaced the pick up coil today. Same thing, started up. Ran for a few minutes and died.

I'm not sure where to go from here. When it did start. It started very smoothly and ran smooth.

maddogs1965

Have you checked out the fuel pump pressure?

Sounds like your electric fuel pump has taken a crap.

Remove the air cleaner housing at the throttle body, and shoot a little staring fluid down it, if it fires off on the starting fluid, i would say your pump is done for. Some times when they are cold, they will fire up and work a little bit before the quit again.

SpitFire

I'm checking that later on today. I can hear it click on when I turn the key, but that doesn't mean it's working.

Also replacing the fuel filter

SpitFire

ok, tested and it seems I am not getting power to the coil. I'm guessing it's in the wiring harness itself? or maybe the brain?

The dash lights and such function properly and all the fuses have power. No check engine lights.

What I know for certain.

1. Installed new wires and distributor..... Jeep started and ran for 3-4 minutes then died.

2. installed new coil ..... Jeep started and ran for 3-4 minutes then died.

3. installed new pickup coil..... Jeep started and ran for 3-4 minutes then died.

I'm at a loss

EDIT - it is getting fuel.

Rjmils

Cps sends signal for ignition so may be that

Red River T

It sure sounds like something such as the fuel pump heating up after it runs a few minutes and then getting "sticky" inside and either quitting or slowing down so that the pressure drops way off. Or maybe it is the engine coolant temperature sensor signal to the computer. If the wires got jarred loose, maybe the signal is bad and once the temp gets to a certain level, there is a spike signal and the computer reads that as "You're WAY to hot, shut off".

On that note, I guess it could be the wiring harness connector plugs to the PCM got jarred and aren't making as good of contact as before, so the temp signal is being distorted.

Wait a minute! I recall reading a thread where the guy said if it starts and runs a bit, then shuts off, the first suspect is the security system.

Red River T

Another thought, can you run these without a cat if you don't reprogram the computer? Is there an oxygen sensor behind the cat? (I don't think so)

Maybe it runs long enough to get to normal temperature and the computer says "Now Signal X ought to be __, and it's not. That means there's a major malfunction, so shut off."

Rjmils

Yes u can I don't even game a sensor plugged into the one in my drive way... behind the cat starts and runs fine

SpitFire

Not going to say for certain, but I thought about the alarm system as well. I had problems with that over a year ago. I thought I had fixed it.

Just went out and did the whole back and forward thing with the key. Now the Jeep has been running for about 5 minutes ....


Edit- Just drove it around the neighborhood about a mile or so. No issues .... I'll have to look into that alarm system a bit more. Looks like you were correct Red River.

Red River T

What is the backward & forward thing with the key? I haven't read about that.

SpitFire

yes it was. It's been over a year since I read the article/post on it. I'll see if I can find it again.

I believe I have an issue with the battery being drained when the Jeep is off. I've been checking it and all seems good so far. I may just be imagining it. Got new plugs and filters on the way.

EDIT- Ok, The jeep is back to not starting and no juice making it's way to the plugs. Same position as before. My only guess is the alarm. My understanding is the ignition system is tied in with the alarm system, so I am going to try the purple/yellow wire trick in the morning.

SpitFire

Have to pull the PCM and check it. The alarm system is not the issue.

Next steps

1. Check PCM
2. Crankshaft sensor
3. Neutral Safety Switch just for kicks

Rjmils

I fixed a grand by cleaning up the pcm plug ins and zip tying them I'm tighter

dave1123

There is one other thing you can check. Put a pressure gauge on the fuel rail, start and run it. If the pressure fades slowly, it may be you stirred up some sediment in the tank which is plugging the pump pick-up screen. this sediment will slowly settle out and give you good pressure until you run it again. If you've got good pressure when it shuts off, it's electrical.

If it was the alarm system, it would shut off within 2 seconds after starting. If it is the NSS, it wouldn't crank. Try swapping the ASD relay with a headlight relay. The ASD relay powers the fuel injectors, ignition coil, and 02 sensor heaters. It depends on the CPS signal to tell if the engine is running and is controlled by the PCM. It will also drop out if the alarm is set.

SpitFire

Going to be removing the PCM in a few days to clean and inspect it. The Jeep is currently at my brother in laws.

All of that has been done. All I have left to check is the PCM and CSS. I'll post back in a few days with pic's of the PCM if there is any damage /broken solder. I suspect that may be the issue since I hit that huge pot hole. Been having starting issues ever since.