Like under my 02 back& fourth relay box theres no connection what so ever, to even put a fuse! U eva heard of that?

 

CA emissions Jeeps have 2 more O2 sensors then the rest. Are you sure they aren't just the placeholders for those? Cruiser54 has FSMs on his site for wiring diagrams.

 

Okay, later models have an 02 sensor heater that requires a fuse. California emission vehicles have these to warm the sensors to make them start working quicker. If your 02 sensor has 4 wires, it's got a heater in it.

 

I have a 2000 Jeep Grand Cherokee laredo 4.0. Changed the pump, filter turminols clean and connected , put seafoam. Drove ok i been all thru google cause i dont have the $ to guess. Well my jeep is GREAT at long distance drives, but the minute i stop the ignition it wont start. The check engine light turned on now and the gauages was going all over a couple times while trying to get it started. Eventually it does start! I had some one say start with the distributor and cleaning all 3 grounds?? If not run a wire from a connection on the battery down the passenger side! Can someone who had a jeep confirm this?

 

Here is my issue. The jeep stalls out at random times. Going down the road and it dies. no sputtering or anything, just off. There doesnt seem to be a rime or reason to it. The only time I can get it to stall predictably is if its in 4 lo and I hold brake and give it gas, or if going down the road I floor it, then it stalls.

 

These are typical symptoms of a failing CPS or loose connections in the CPS connector plug. Normally I would suspect the CPS itself, but by torquing it up in reverse you're probably stretching the wire harness causing the loss of connection. You might want to check your motor mounts also.

 

Thank you. I will check it per the write up on here and see. I looked at the motor mounts..... add that to the list of things to get.

 

Hi folks,

I've got a '98 ZJ 4.0 that won't pass emissions. Turns out the PO cut the Cat and downstream O2 sensor out at some point in the past. This is a project for me and the first time it's needed inspection since getting back on the road.

The upstream sensor is intact. What I can't figure out from the various forums, manuals, and lots of time with a flashlight is where the wires come from that connect to the missing O2 sensor. I can't find any open wires, empty plugs, or anywhere to plug in the new sensor.

Does anyone have a '96-'98 ZJ that could look for me and figure out where on the harness the rear O2 Sensor daylights?

Thanks!

 

IDK if my 97 ZJ had it like this, but my 97 Dodge Caravan had a big round rubber plug in the floor near the converter, with the wires in it, that you pulled out and the connector plug came out of the floor so you could change it.

Okay, looking at the part online, it just shows a short wire harness with a cannon plug on the end. Round, 4 pin.

 

Looking at the 1997 ZJ FSM, the downstream O2 sensor wiring is tied into the transmission harness. There's should be a split over the transfer case, one branch goes to the speed sensor, one to the 4WD switch (for running the dash light) and the other to the O2 sensor.

(8W-90-15)

 

Thanks...that should help....hopefully it's still there and not cut off short!

 

Thanks all for the help and suggestions. Turns out it was stuffed up over the T-Case and best of all it's still intact...no cutting! Now replace the Cat and downstream O2 sensor and I'm back in business.

 

Hello Fellow Jeepers,
I am working on my 1996 zj grand Cherokee it has a 1998 4.0l engine and 255,000 miles is requiring more attention. The following is start to end of why I am contacting all you good people.
Everything was great until the 4.0l thru a belt dew to the air conditioner by pass pulley bolt coming loose. I repaired that but from that point on it wouldn't start without jump. Which I did twice. Then when I tried to start it i got rapid clicks in the area of the starter and battery. Like the starter wouldn't turn. So I jumped it again. It started. I put the battery on the charger overnight. Next morning I concluded that it was a dead battery. Tested the battery and it was completely dead.
Okay I pulled a optima battery out of a dune buggy. Made sure it had a full charge and installed it in the jeep. Made sure the termals were clean and tight. Went to hit the key and nothing. This time no power at all no power to the dash, no fuel pump and nothing under the hood. I am completely stumped?
Any information, ideas and or testing prosecutors would be greatly appreciated.
Thanks in advance, Jon

 

Test the battery for voltage ON THE POSTS, not the cables. Then check the voltage at the red wire on the PDC (Power Distribution Center, box under the hood)to ground on the body. I'm thinking the battery cable clamps are the problem. Look for green corrosion where the wires enter the molded terminals.

 

guys, i'm looking to buy a wj, but I just noticed the one i'm looking at is not 4wd, its awd. I wanted to build something that i could take off road and too the beach to fish, is awd going to be an issue to modify and lift vs 4wd? I hope what i'm asking makes sense.