Rough idle, tried everything
Thread Starter
Newbie
Joined: Feb 2017
Posts: 14
Likes: 0
From: CT
Year: 2001
Model: Cherokee
Engine: 4.0
You are right as there is no distributor in the sense that we normally know. These models have what amounts to be a distributor with the cap cut off. The Cam sensor is mounted to the top of the distributor shaft housing so it receives the signal from the camshaft then tells the coil packs to fire in order. My neighbors problem was the Cam sensor was sending erratic signals to the coil packs causing idle issues. This smoothed out above 2000 rpm.
CF Veteran
Joined: Aug 2009
Posts: 1,126
Likes: 30
From: Detroit, Michigan
Year: 1998
Model: Cherokee
Engine: 4.0
Get a large can of starting fluid. Spray in bursts, at each vacuum line and connection while the engine is running. If it revvs up the engine, you found your vacuum leak. Spray the cannister the connections go to also. Some rust right through. Good luck and keep us posted.
Thread Starter
Newbie
Joined: Feb 2017
Posts: 14
Likes: 0
From: CT
Year: 2001
Model: Cherokee
Engine: 4.0
Get a large can of starting fluid. Spray in bursts, at each vacuum line and connection while the engine is running. If it revvs up the engine, you found your vacuum leak. Spray the cannister the connections go to also. Some rust right through. Good luck and keep us posted.
Newbie
Joined: Feb 2017
Posts: 23
Likes: 0
Model: Cherokee
Did you find vacuum leak? Was coil pack and injectors you used new or used? Did you figure out what the fuel trim numbers are? When spraying the starting fluid be sure to spray around injector o-rings, especially the #3 and #4 cylinder injectors.
Thread Starter
Newbie
Joined: Feb 2017
Posts: 14
Likes: 0
From: CT
Year: 2001
Model: Cherokee
Engine: 4.0
Checking the vacuum leak tomorrow morning, I'll update then about vacuum leak. Gonna try to get my hands on my neighbors fuel pressure tool tomorrow too!
Thread Starter
Newbie
Joined: Feb 2017
Posts: 14
Likes: 0
From: CT
Year: 2001
Model: Cherokee
Engine: 4.0
No vacuum leaks. Haven't gotten the tool to check fuel pressure. Still running like ****. Wrapped the fuel rail though so hoping to avoid any future problems with heat soak