Novak Conversions Jeep Wrangler TJ radiator

97 TJ 2.5 Start Issues

RDF

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Jan 7, 2024
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Hey guys,
Ive got quite a issue that has stumped me.
Its a '97 2.5L Manual.
Engine would spin but not fire up.
Found the distributor cap stud where the coil wire connects was compromised. The stud was moving around in the cap.
Replaced cap with no luck.
Started down this rabbit hole and its confusing.

New crank sensor, checked power, ground and signal. All good.
New distributor with new cam sensor, Checked power, ground and signal. All good.
New Coil, Wires, Spark plugs.
Jumped ASD relay
Tried 3 other PCMs from buddys jeeps.

I tested crank and cam sensor signals with meter while slowly turning engine over with a wrench on crank. Power and ground to sensor also was consistent, meter readings didnt do anything crazy when the signal wire showed a signal.

The only way i can get it to fire up is to take the wire from coil to distributor,
Disconnect the dist side and put a spark plug in the wire.
Touch spark plug to battery ground.
Jump out the starter relay so i can watch the spark plug. Once is see a spark i can connect wire back to dist and it will fire up and run great. No problems driving it around for hours.
Turn engine off and then it will crank up 50 times in a row like its new. But if it doesn't fire up, i have to do the spark plug to battery trick a few times.
Last night i couldn't get it to fire up so i disconnected the black connector to PCM and plug it back in, Try the spark plug trick and then eventually it will fire up.

I used a Autel Scanner and all i can see is the crank/cam is not sync or out of sync. It reads rpms when cranking tho.

After using the scanner i tested the crank/cam signals at the PCM with 2 meters to make sure both were sending signals.

Im stumped. Ive used Alldata to use their diagnostics for this and everything checks out.
Last night i got it fired up and shook the wiring harness for several mintues while it was running and it didnt skip a beat.

What do i do now?
 
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Forgot to mention last week when i got it running i drove it for 84 miles no problem. On road and off road trying to bounce something around to see if it would hiccup.
 
I have nothing to offer, but will watch to see what others suggest.

Welcome to the forum. Check out the 97 thread and the 2.5 thread in my signature line and let us know if you have anything to add to them.
 
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Anyone?
I did the spark plug trick in the coil wire and when i disconnected the black PCM connector i got a spark, but not when turning engine over.
2nd time i disconnected the PCM the thing fired right up and ran great.
 
All I can think of is throwing a Standard Motor Products crank position sensor at it.

Cam position sensor is in the distributor...lots of threads about those slipping and doing crazy shit...so maybe time to throw a distributor at it... careful cause some of them are 180 out from the factory.

Last thing is send your PCM to @Wranglerfix WranglerFix.com Mark for testing to eliminate the PCM as the issue.

-Mac
 
I tried a Standard brand and also one from the Stealership. No luck.

Also borrowed a Dist out of my buddys 2.5L and no luck.

Its going to be getting a 4.8L here soon since ive wasted all that time and money trying to get it to run.

Anybody want a 2.5L? Runs great when you can get it to fire up.
 
Finally found the fix for this issue.
Pulling the engine out of it next week and sending it to the scrapyard.
Freshened up a 5.3 for him and a 4L60E so just got to find a input gear for the transfercase and can get this show on the road.
 
Novak Conversions Jeep Wrangler TJ radiator