2007 JK Intermittent Start Issue

Eagle5

Eagle5

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Jun 27, 2021
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3
Location
St Louis
I've got a 2007 JKU Rubicon with a 4.7L swapped engine. It will start fine if I put the key in the ignition and immediately start it. If I delay a bit (listen to the radio with the key in the run position) , it won't. If I kill it while shifting, it won't. I have to take the key out and let it sit for ~1 minute, then I can start as stated previously. I'm pretty good at electrical stuff, but I can't figure this one out. It looks like the PCM and the TIPM work together to get the starter engaged. The PCM grounds the relay, and the TIPM supplies 12v. It seems like the PCM tells the TIPM when the Clutch is pressed. I've tried and checked everything I can think of and can't figure out if its the PCM, the TIPM, or something else. It looks like the Clutch Pedal Position switch is okay. I have a scanner the lets me know that the TIPM is seeing the ignition key move to "start". I can start it directly by supplying 12v to the solenoid.

I would appreciate any help!
 
BLACKJKU said:
If it was mine i'd just bypass the safety clutch relay so it will start anytime.
Click to expand...
I don't think it has to do with the clutch. The PCM reads the clutch position and energizes the starter relay, and I don't think its getting hung up on the Clutch Position Switch. The clutch is working okay. I could create an new starter relay outside the TIPM, but JKs don't have an actual "start" ignition wire that I could find in the wiring schematics.... its all bus communication!
 
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