Help needed for a new Jeeper: TJ won’t start!

Try cycling the ignition and priming the fuel pump repeatedly. After doing that 3-4 times, does it then start right up?

If so, it's your drain-back valve in your fuel pump.
 
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Could be something to do with me bypassing the starter control wire in the ignition assembly because of the common piece of metal that snaps not allowing the control wire to make contact to the starter.I hooked up a control wire to a toggle switch that I use to turn over the engine.
 
Try cycling the ignition and priming the fuel pump repeatedly. After doing that 3-4 times, does it then start right up?

If so, it's your drain-back valve in your fuel pump.

This is what I think is going on with mine. Sometimes it will just crank and crank. If I stop trying to crank and turn the key off and then retry starting it, it will start up no problem. I have even began to just turn it over just once, then stop and turn key off and restart. Other then that I have no issues. One day I will have to replace the fuel pump I guess. For now, it is doable the way I am doing it. LOL :D
 
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So I have an update for all that have been wondering. My shop wanted me to proceed with getting a warranty replacement ECM from the company I originally ordered one from just for trying it out. I just dropped the replacement off, they plugged it in and it started right up. They are going to button things up and run another scan on the Jeep to see if anything else comes back. Fingers crossed we are good to go.

Who would have figured 2 bad ECMs???The original and the replacement.

Thanks for all feedback, hopes, and prayers.
 
Just had almost the exact same symptoms on my 99. I replaced the fuel pump and relay and still it would die while driving, this time wouldn't start back up and at my waits end I towed it to the shop.
They replaced the crank position sensor and cleaned up the wiring about 12" from the fuel pump. Still, would run for a few minutes and die. They said the ECU was bad, luckily I had found this forum and had some info/questions to ask, they couldn't answer and so I took it home and started from scratch, literally. I sanded down every ground location I could get to, put things back together and have been fly-n-hi for a few days now.
Cant over emphasis the importance of clean ground even if your test lite says they are good.
Hope this isn't considered hijacking this thread but wanted to update my post here as it turned out to be something else that was causing my JT to die after driving for a while and intermittent crank/no start.
After taking it to an auto "electrical specialist" who said it was my alternator, laughing at him and towing the jeep home, I found a bare wire that had rubbed the insulation off on the back of the engine block. Repaired the wire and zip tied the harness up and out of the way. After that and a few more grounds cleaned, I have had no problems. Well, at least no more of those problems, nut I will open a new thread for what is going on now :)
 
Okay all, so a new update here. 7 months later and still dealing with the issue. I am now onto the 4th ECM, every time has been a separate set of issues. This most recent ECM is the most promising being that......

1). The fuel pump primes when the key is turned on (before the fuel pump ran constantly and did not start).
2). All gauges respond and all dash lights turn off (before none of this happened).
3). The Jeep starts and sounds beautiful every time (it barely started and idled rough before).

Now the problem is after the Jeep starts it dies about 2-3 seconds later but always restarts. If I rev the engine to try to keep it running it revs then dies. When this happens the exhaust smells like pure gasoline.

Any thoughts???
 
Okay all, so a new update here. 7 months later and still dealing with the issue. I am now onto the 4th ECM, every time has been a separate set of issues. This most recent ECM is the most promising being that......

1). The fuel pump primes when the key is turned on (before the fuel pump ran constantly and did not start).
2). All gauges respond and all dash lights turn off (before none of this happened).
3). The Jeep starts and sounds beautiful every time (it barely started and idled rough before).

Now the problem is after the Jeep starts it dies about 2-3 seconds later but always restarts. If I rev the engine to try to keep it running it revs then dies. When this happens the exhaust smells like pure gasoline.

Any thoughts???

Dude this thread sucks! I feel for you, even though it's a toy and not a daily driver it's basically an anchor. Your paint and rims look cherry, you need to get this thing sorted and on the road (or dirt)!

I had an identical symptom that you are now describing on an old Cherokee with the 4.0 that ended up being the ASD relay. Head over to the TJ Resources forum, download the PDF manual for your '97, and cntl+f for "ASD" or "automatic shutdown".

Has your shop indicated whether it looks like this thing has had an extensive amount of work done? Perhaps wiring harnesses that look as though they have been reworked, lots of aftermarket equipment, or accident damage?
 
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Thanks for
Dude this thread sucks! I feel for you, even though it's a toy and not a daily driver it's basically an anchor. Your paint and rims look cherry, you need to get this thing sorted and on the road (or dirt)!

I had an identical symptom that you are now describing on an old Cherokee with the 4.0 that ended up being the ASD relay. Head over to the TJ Resources forum, download the PDF manual for your '97, and cntl+f for "ASD" or "automatic shutdown".

Has your shop indicated whether it looks like this thing has had an extensive amount of work done? Perhaps wiring harnesses that look as though they have been reworked, lots of aftermarket equipment, or accident damage?

Thanks for the info! I will definitely pull it up. My shop is stumped, but it’s not on the clock and they are just playing around with it as they can. They last indication they gave to me last week is they they feel it may be the opposite end of the crank sensor? So the plate on the flywheel that it reads off of. I was told that they had one other situation that was similar and after exhausting all options they discovered the plate came loose.

As far as electrical, this used to be my field. I was MECP certified back in the 90s and specialized in mobile electronics. There is a lot I cleaned up as far as add ons and even cleaned up some broken factory wiring. In all the wiring is now pretty clean for 22 years old.
 
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Okay y’all, 10 months of work here and I finally have an update!

5 ECMs (3 different companies), 1 coil, 1 map sensor, and 1 clogged cat later and I finally have the Jeep running again. It seems like a culmination of things that threw everything off.

From my experience if anyone is ever in need of an ECM contact CarComputerExchange.com. After all the electronics was figured out the final piece was the recently replaced catalytic converter. So finally I settled on running a straight exhaust with bungs welded in for the factory O2 sensors.

So far all seems to be great!

Thank you to all for your insight.
 
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