Hey y'all. Okay bear with me kinda long just trying to be thorough. Been searching Google and every Jeep forum for a while now and can't find an answer to the problem with my 1998 Cherokee 4.0L. About a month ago I was driving on the highway about 50mph when the Jeep gave a couple quick bucks. The next day it died at a stoplight. Bucked and then died while in reverse a few times.
Cleaned the TB and IAC after that. Drove around the next couple weeks (mostly under 50 and some trips up to 65mph) and everything was peachy.
Drove 6 hours to Spokane bucked maybe a couple dozen times on the highway real quick like half a second then it was fine. Finally threw a P1391 code during the last hour of my drive. Searched on the forums for solutions, thought it might be a bad Crankshaft Position Sensor (bought havent put in). Next day I cleaned all the grounds EXCEPT the braided one on firewall. Why? I noticed it was connected to the firewall and the other end was resting on the exhaust header! I discovered it really connects to the last head bolt. "No way. Could this really be why I'm having these issues???" So i reconnected the ground the head bolt. What an easy fix!
It wasn't.
Oh boy. The Jeep was not a fan of that ground being reconnected. It was hard to start had to give it gas and once it started it up began misfiring, choking and eventually backfired through the intake!Disconnected the ground again everything was fine!
Noticed there was a bolt missing on the bellhousing right where the CPS is, so I replaced that. Cleared the CEL and drove another 3 hours to Missoula and everything went smooth no bucks or CEL.
I'm guessing there is probably an electrical short somewhere. I don't know where to begin. The O2 sensor wiring sheathing had melted a couple years ago but thats been fixed.
Cleaned the TB and IAC after that. Drove around the next couple weeks (mostly under 50 and some trips up to 65mph) and everything was peachy.
Drove 6 hours to Spokane bucked maybe a couple dozen times on the highway real quick like half a second then it was fine. Finally threw a P1391 code during the last hour of my drive. Searched on the forums for solutions, thought it might be a bad Crankshaft Position Sensor (bought havent put in). Next day I cleaned all the grounds EXCEPT the braided one on firewall. Why? I noticed it was connected to the firewall and the other end was resting on the exhaust header! I discovered it really connects to the last head bolt. "No way. Could this really be why I'm having these issues???" So i reconnected the ground the head bolt. What an easy fix!
It wasn't.
Oh boy. The Jeep was not a fan of that ground being reconnected. It was hard to start had to give it gas and once it started it up began misfiring, choking and eventually backfired through the intake!Disconnected the ground again everything was fine!
Noticed there was a bolt missing on the bellhousing right where the CPS is, so I replaced that. Cleared the CEL and drove another 3 hours to Missoula and everything went smooth no bucks or CEL.
I'm guessing there is probably an electrical short somewhere. I don't know where to begin. The O2 sensor wiring sheathing had melted a couple years ago but thats been fixed.