nhrocker
Jackstand wheeler
- Location
- Claremont, NH
I apologize in advance, this is going to be a pretty long description. Hopefully someone has some experience with this and can help me out?
First, I've got a 95 with the 4.0, auto, 231.
Friday night last week I went to test drive my XJ after doing some work on the rear suspension/exhuast/driveshafts. I noticed on the drive that it felt like it had lost power and acceleration, but after shutting it off and turning it back on it felt fine. Then next morning on the road after about 50 min of driving speeds of 45-55mph the RPM's started going way up and the speed started dropping fast. Right as I pulled to the side of the road it ran ragged and then stalled. I saw a small amount of smoke seem to come from behind the dash and some from under the hood. I got out, popped the hood and watched a small electrical fire die out, about the location where the wiring for the sensors on the throttle body and CPS branch out of the wiring in the plastic rail that runs next to the valve cover. After seeing that and how melted/burned the wiring was I didn't touch anything and had it towed home.
I've now pulled it apart to trace wires and compare them to some wiring diagrams. While all the wires were burned/melted to some degree, there are a number of them which had the insulation burned clean off. Large sections, like 6" or more, and all right near each other in the bundle. I figure they were they hottest, so possibly the cause of this.
Bare wires:
Injectors- dark green w/ orange tracer (from splice where all the individual wires join towards the main harness bundle along firewall)
CPS- grey w/black tracer
CPS- orange (1 of the 3-from splice where they separate and head into the main harness along firewall)
CPS- black w/light blue tracer (from near plug to the splice)
O2- black w/light blue tracer (small section, might just have been damaged by me pulling apart the harness to inspect)
The rear engine temp sender was also broken, with the top of the sender and the plug ending up melted into the plastic rail that holds the wiring harness.
I got the section of the harness that's damaged from a 94 I plan on grafting into mine to repair it, and a full harness out of a 95 on its way to me as a spare.
My concern is that I'll go through the work of repairing the wiring just to still have the cause there (if it wasn't the wiring itself) and burn up my repair work and/or the new harness. What could cause this?
Thanks in advance
nhrocker
First, I've got a 95 with the 4.0, auto, 231.
Friday night last week I went to test drive my XJ after doing some work on the rear suspension/exhuast/driveshafts. I noticed on the drive that it felt like it had lost power and acceleration, but after shutting it off and turning it back on it felt fine. Then next morning on the road after about 50 min of driving speeds of 45-55mph the RPM's started going way up and the speed started dropping fast. Right as I pulled to the side of the road it ran ragged and then stalled. I saw a small amount of smoke seem to come from behind the dash and some from under the hood. I got out, popped the hood and watched a small electrical fire die out, about the location where the wiring for the sensors on the throttle body and CPS branch out of the wiring in the plastic rail that runs next to the valve cover. After seeing that and how melted/burned the wiring was I didn't touch anything and had it towed home.
I've now pulled it apart to trace wires and compare them to some wiring diagrams. While all the wires were burned/melted to some degree, there are a number of them which had the insulation burned clean off. Large sections, like 6" or more, and all right near each other in the bundle. I figure they were they hottest, so possibly the cause of this.
Bare wires:
Injectors- dark green w/ orange tracer (from splice where all the individual wires join towards the main harness bundle along firewall)
CPS- grey w/black tracer
CPS- orange (1 of the 3-from splice where they separate and head into the main harness along firewall)
CPS- black w/light blue tracer (from near plug to the splice)
O2- black w/light blue tracer (small section, might just have been damaged by me pulling apart the harness to inspect)
The rear engine temp sender was also broken, with the top of the sender and the plug ending up melted into the plastic rail that holds the wiring harness.
I got the section of the harness that's damaged from a 94 I plan on grafting into mine to repair it, and a full harness out of a 95 on its way to me as a spare.
My concern is that I'll go through the work of repairing the wiring just to still have the cause there (if it wasn't the wiring itself) and burn up my repair work and/or the new harness. What could cause this?
Thanks in advance
nhrocker
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