zumer715

I've been trying to chase down an issue for about four months now and it's driving me crazy. I've even had it in to Jeep and they say it's a harness issue. Anyways here we go....
Symptoms
-rough running
-speedometer needle jumps all over the place when running (started after taking it to Jeep)
-very difficult to start -seems to be misfiring intermittently
-sometimes stalls
-IMPORTANT (I think) It keeps blowing this fuse when it quits running and I do not know why. Using an advanced electrical testing probe I've found that both of the terminals for this fuse are grounded and nothing changes with the ignition on... I am not sure if this is significant but that's what I've found.
Parts replaced
-coil packs
-injectors
-ECU
-cam position sensor (and re-indexed)
-crank position sensor
-engine temp sensor
-TPS
-IAC
Any help is greatly appreciated. Thanks guys

zumer715

Here's a video of what it does, it normally runs tougher than that and the exhaust is loud cause I disconnected it before the cat to eliminate a clogged cat as the problem

BillyBoy

Start it. Wiggle the main wiring harness that runs left to right in the engine compartment above the engine. See if it changes the idle or stalls it. I had the same problem. Cost me 200 at the dealership for a new one. The wires in it dry rotted and rubbed until exposed.

You also might want to do cruisers ground cleaning trix.

zumer715

That's exactly what it did. What was your fix? Just replacing the bad wires?

BillyBoy

They replaced the harness. About 200. Run it. Wiggle it... wear gloves. Might not even be the problem. All I'm saying is that I chased an electrical problem with sporadic symptoms by throwing all new parts and hours of my labor at it.

Clean- refresh the grounds first. Then check-wiggle wires. I also had a problem with the connection to my coil. When I wiggled that, she died. Wiggling is a cheap easy way, if not all that scientific to check.

zumer715

I found a spot in the harness where the wire coming from that fuse and controlling ignition and injection had melted the insulation and was grounding out on 2 ground wires. I repaired all the wires, plugged it back in, and she fired right up!

BillyBoy

Amen!

Yetti53

which harness I’ve been going crazy searching for this issue