So, I rebuilt the motor, back in septemeber and replace the cooling system. She has been running like a bos; started up, just at the flick of the key. This morning, I was heading out to a side job and approoached a stop sign; I sat there a little longer than usual. She quit. I tried to start her back up... No bueno! When I turn it over, the starter sounds promising, it just doesn't fire. But it sure sounds promising when I try to turn it over. Can any internet mechanics take a guess at what the problem is? The spark plugs are new (since september), the wires are less than go years old. The coil is new (acceleration super coil). The distributor is original, since I bought it. It all checked out good, before I reinstalled it.

 

Is the check engine light on? If so, what code?

And if it's a crank but no start situation you're either missing fuel, spark, or compression. I would start with checking spark and fuel first and report back.

 

Check the fuel pressure

 

No CEL. I did manage to get it to start, but I had to gas it to start it, but it stalled just as quick as it started. So I gassed it and started it again and held the gas down to let it warm up, then let off the gas. Then it would idle for about three minutes and die.

 

Sounds like a fuel pump.

 

Battery / alternator? I had my Jeep out of service for a couple of months to redo the front suspension, and when I finally started it up, battery was dead and so was the alternator - they don't like waiting. What makes me think this is that you got it started, had to hold the gas pedal down, and then died. As if the computer is not getting a charge.

Or the fuel pump. But when you change so many parts at once, any one of them could be doing you wrong.

Btw, really liked your thread on the rebuilt motor.

 

Batteries new. Alternators new.

Update... I went out to start it up, to move it, yesterday. It fired right up and ran. Shut it down and started it right back up and moved it. Then I shut it down and started it back up again, and let it idle for a while. The idle seems to be a tad lower (around 750) and honestly seems to be running smoother. Not that it was running rough before. It's like a car that you can barely tell it's running. Anyway, later last night, I drove it to a friends house and we did a pressure test on it. It showed 38 to 39 pounds... Although the pointer did a little dance. Like it was vibrating between 38 and 39.

 

Scratch that... I was driving it and sitting at a light and the idle just decided to drop out and I couldn't get it started. Some people helped me push it to the side. When I got it pushed to the side, I got it to start up again and drove to my destination. I was gassing it at red-light, to keep it running. When I pulled in to my destination, it stalled again.

 

I think the recommended fuel pressure at the rail, in idle, is 49 psi (with a variance of 5 in either direction). Lower than that may be indicative of trouble.

The AIC (air intake controller) may cause it to die while in idle if dirty or defective.

 

I believe the obdl pressure is supposed to be 39... I don't have my fsm available at the moment.

 

My jeep would randomly die and sometimes Start right back up sometimes not and it was the cps. I've also had a dead battery where I had to keep on gas or it would die.

 

Battery is good, alternator is good. Replaced the battery in may, then it was down until September, when I rebuilt the motor and ended upI replacing the alternator. Battery checks good. Alternator works excellent. Cups... Maybe. I also installed a new tips and iac valve in September.

 

tow truck is heading over to take it to the mechanic. I disconnected the battery to reset the Computer for an hour. Hooked it back up and it started right back up and I let it idle for 10 minutes to get up to temp. Then I shut it off. Tried to start it back up and it just wouldn't fire. It almost sounded like it was gasping for air.

 

I see in your sig that you have an adjustable map sensor. Did you try adjusting it to see if there are any changes.

 

Yes