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It just died

Well I will re-thing the CPS. I was under the impression it was a work / not work part. Except for the wire. If the wire is messed up I can see where it would short. But ok. The one on there is fairly new.
 
Well I will re-thing the CPS. I was under the impression it was a work / not work part. Except for the wire. If the wire is messed up I can see where it would short. But ok. The one on there is fairly new.

Is the one on there new? I thought you put the old one back on on the side of hwy 97. Unless you changed it out after that?
 
I disagree. I have seen way to many intermittent CPS's. Many times it is due to corrosion on the connector, but they just get flakey. I had one that would allow you to start but it wouldn't allow you to rev past 1200 rpms. With them being probably the highest failure rate item on an XJ, I would grab one and swap it. If it doesn't fix it, put the old one in a baggy under the back seat for when it does crap out.

Two questions

1. What causes the CPS to crap out?

B. Can you test them to see if that is actually the problem?
 
Testing a CPS without an oscilloscope is hit and miss. Double check the wire didn't get up next to the exhaust and get toasted.
 
So last night I went through allot. I checked and cleaned all the sensor connection. I took out the battery and cleaned the terminals, all the connections both at the battery and at the places where they bolt to the jeep for ground. Checked the cap & rotor ( they looked great ). Took out all 6 plugs, looked great. I cleaned them re-gapped them and put-um back. Then I checked the CPS wire and CPS. The wire looked fine, the unit was tight bolted to the trans.

While messing around with the wire I noticed the MAP sensor tube was not all the way on ( the firewall connection ). Not only was it not all the way on, but the tube was clogged with crap. I replaced the cheap jeep plastic tube for rubber. After cleaning it out and re installing it, jeep started right up. Seemed to run great, never died or stalled. Now im not saying this was the problem on the trail, but it did make a difference after I cleaned it and hooked it back up.

Old Man, the one I have on the jeep is a factory. It started factory, then I swapped it out a year or so ago when I lost all power ( it was a bad coil ) then on the hwy 97, I swapped the CPS again. And again it was the coil. With the MAP sensor un hooked the motor ran like crap then just died, so maybe on the trail it was just barley hanging on, and that why it died randomly.
 
Mudderx, thanks for the post. I printed it out and will put in my binder. I will say with long arms & lift, getting to the CPS & changing it is about a 15 to minute job. So swapping in a new one is no big deal. Except for the cost.
 
The MAP hose is a perfect match for your symptoms. I would run that for a while and see if the problem goes away.
 
The MAP hose is a perfect match for your symptoms. I would run that for a while and see if the problem goes away.

Cool. I feel a little better now. See back a while ago I noticed the plastic one, if you slightly bent it up to a light it looked like a spring. Just cracked all the way up & down. So I replaced it with rubber tube. I also did the same to the tube that comes off the PVC valve at the valve cover. I replaced it with 5/16 break line into the manifold. Super simple to keep that cleaned out.
 
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