TJ cranks but won't start

Mannyp2711

New Member
Joined
Mar 31, 2022
Messages
6
Location
Miami
So long story short i have a 2000 Jeep TJ 4.0 194K miles. A few weeks back it started giving me issues turning on but it would turn on in like 3rd or 4th try. Maybe 3 weeks ago it stopped turning on it would crank crank and not turn over. I got on all the forums and pointed me towards either TPS or Fuel Pump. I ended up replacing both with a new Fuel Pump and new TPS. The jeep turned on after but again after 3rd or 4th try so still was not normal. I saw other forums that pointed towards crank position sensor so i changed that one and it started turning on normally after first try (most of the times NOT all). Last week started giving issues turning on again and yesterday went back to crank but not turning on. My mind went to maybe spark? So i pulled out a plug and tried the trick to turn the key over and hold the plug on a ground to see if it sparks (NO spark). Not sure what that should indicate? I also went ahead and swapped the coil pack from my brothers jeep (same model jeep) to see if maybe that was the issue and no change there either.

Can anyone else give any ideas im going nuts trying to figure it out.

Thanks
 
If you have no spark, then I would check the ASD relay. Lots of stuff can make that thing be a "problem" but lets first figure out if thats a problem. Have someone put their finger on that relay and try to start it. Does it click on, and then back off? Or not at all? While your helper is there check the fuel pump relay too.

Also, check ALL your fuses. Don't forget the ones in the glovebox.
 
If you have no spark, then I would check the ASD relay. Lots of stuff can make that thing be a "problem" but lets first figure out if thats a problem. Have someone put their finger on that relay and try to start it. Does it click on, and then back off? Or not at all? While your helper is there check the fuel pump relay too.

Also, check ALL your fuses. Don't forget the ones in the glovebox.
So for both ASD and Fuel pump I should feel a click when the key it’s turned to the on position or when the car is actually attempted to turn on?
Thankyou!
 
100% on the fuel pump, 95% sure on the ASD. The only time I had an ASD problem it was actually unrelated so I never have really done any troubleshooting on that circuit. Maybe I should just go check mine real fast. brb
 
yes, turning the ignition ON will make the ASD relay click. If you don't start the car within 1.8 sec you'll feel it click back off. If you don't feel it click, swap it with the fuel pump relay in order to isolate if its a bad relay or a problem in the circuit.
 
100% on the fuel pump, 95% sure on the ASD. The only time I had an ASD problem it was actually unrelated so I never have really done any troubleshooting on that circuit. Maybe I should just go check mine perfe
yes, turning the ignition ON will make the ASD relay click. If you don't start the car within 1.8 sec you'll feel it click back off. If you don't feel it click, swap it with the fuel pump relay in order to isolate if its a bad relay or a problem in the circuit.
Perfect I’ll go check mine out in a bit don’t have a second person to help out right now and I definitely can’t run to the relay in 1.8 seconds either hahaha but again thank you and I’ll keep you updated
 
Perfect I’ll go check mine out in a bit don’t have a second person to help out right now and I definitely can’t run to the relay in 1.8 seconds either hahaha but again thank you and I’ll keep you updated
Update: came out here to the relays (ASD and fuel pump) both click on and off when I turn the key on. Another thing I might add is since it’s a Manual car I’m able to push it w my brother and start it off first gear. Once the car gets running it drives perfectly fine, no check engine and no malfunctions with all gauges working properly.
 
yes, turning the ignition ON will make the ASD relay click. If you don't start the car within 1.8 sec you'll feel it click back off. If you don't feel it click, swap it with the fuel pump relay in order to isolate if its a bad relay or a problem in the circuit.
Update: came out here to the relays (ASD and fuel pump) both click on and off when I turn the key on. Another thing I might add is since it’s a Manual car I’m able to push it w my brother and start it off first gear. Once the car gets running it drives perfectly fine, no check engine and no malfunctions with all gauges working properly.
 
feels like something in the ignition/starter circuit is the culprit, but I don't have any ideas. I know the ignition tumbler can be problematic. Can you use a remote starter/hotwire it to bypass the ignition? If so, that would isolate the cause pretty well. Need our ignition experts to chime in, or else you'll need to plow through the wiring diagrams.