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XJ Ask the Question Thread
Herp Derp Jerp

Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Wiring seems fine. What would the coolant temp sensor have to do with it running rich though? It heats up normal and stays between 200-210. I actually fixed my code, I cleaned all my injector connections for the 10th time around and I finally got it. How could I tell if the 02 sensor is bad? What else determines how rich it runs?
Fuel mix is set by TPS, O2, MAP, IAT, and ECT sensors. Good grounds are essential as are no vacuum leaks and clean sensors (buildup messes with IAT and ECT). If your O2s are original just change them, they're only good for around 80k miles. New NTK sensors are pretty cheap online.
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
Wiring seems fine. What would the coolant temp sensor have to do with it running rich though? It heats up normal and stays between 200-210. I actually fixed my code, I cleaned all my injector connections for the 10th time around and I finally got it. How could I tell if the 02 sensor is bad? What else determines how rich it runs?
Here's instructions on how to test the MAP sensor. It's from a '94 XJ FSM so I don't if it pertains to the '91 or not. Make sure you check the vacuum tubing to the MAP sensor as well.
Hey yall, I am installing some train horns. I tried to wire them up to my horns and they worked for a bit and then they stopped. Now when I press my horn there is a click that is coming from the glove box area or passenger side dashboard area. All of the fuses internal and external are fine so I am lost as to what this is. Is it a compressor? A bad connection? Thanks yall.
CF Veteran
Joined: Oct 2009
Posts: 2,867
Likes: 16
From: Fauquier County, Virginia
Year: 1991
Model: Cherokee
Engine: I-6 4.0 HO
::CF Administrator::





Joined: Feb 2011
Posts: 14,479
Likes: 805
From: Blunt, South Dakota
Year: 97
Model: Cherokee (XJ)
Engine: 4.6 stroker
Hey yall, I am installing some train horns. I tried to wire them up to my horns and they worked for a bit and then they stopped. Now when I press my horn there is a click that is coming from the glove box area or passenger side dashboard area. All of the fuses internal and external are fine so I am lost as to what this is. Is it a compressor? A bad connection? Thanks yall.
Newbie
Joined: Mar 2014
Posts: 5
Likes: 0
From: clinton missouri
Year: 1989
Model: Cherokee
Engine: 4.0 straight six
Ok i have no power to the brake switch on the pedal where do i go from here i don't kbow alot about electrical I'm at a loss please any info would be great.
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
Relay? What kind of horns? Actual train horns? Real train horns will have a compressor, usually a small air tank, a bunch of valving, and the electronics. Much more involved than just hooking it up to existing wiring. Double check your work, and any relays and go from there. Best I got with limited info...
CF Veteran
Joined: Sep 2010
Posts: 12,692
Likes: 6
From: Mercer County, NJ
Year: 2001
Model: Cherokee
Engine: 4.0L I6 HO
CF Veteran
Joined: Aug 2011
Posts: 1,994
Likes: 8
From: San Jose
Year: 89
Model: Cherokee
Engine: 4.0 I6




