ricracer

I found this by accident I have an 89 MJ which had a bed liner installed . When I removed the add on bedliner , when I closed the doors there was a tinny rattle noise . I was going to bedline it with a Duplicolor armour kit. While I was prepping it someone closed my door and I noticed that the front wall of the bed rattled. It had all the factory spot welds , but the edges weren't connected and caused the rattles. So I welded both corners ,and Man what a difference the rattles went away and so did all the squieks and noises I had heard for several years !!! This tranformed the truck , now it's quiet and solid sounding !

Hey I had the same problems with my 89 MJ when I first got it, the motor was knocking because it had been run hot. When I did a motor swap I just swapped in a new newer 90- Radiator. I already had the new 180 degree thermostat , I found a junk yard overflow tank and heater valve from a newer cherokee. I went with a new waterpump from the year motor I had. The Rad was a bolt in, the tank took about 3 feet of hose and a wire tie to mount . Also I saw that the freeze plugs were leaking which probally caused the whole problem , I switched them out with brass ones. It wasn't hard at all.

Hi Jerry I had the same sounding problem this week with my 89 Comanche with a 95 HO motor but 89 sensors and wiring harness. When it first happened it was at a stop light after starting and driving for about 5 miles like yours .The truck had been running fine for over a year after the swap, except lately when I took off if I stood on it it would sputter and attempt to die if I went more that 3/4 throttle. When I was checking everything it wouldn't fire some of the injectors we had a noid checker( I had my buddy a pro mech. helping me ) but not all of them, we first replaced the cps and it started but then died again and wouldn't start. I tried a used ecu and got it to start again but as soon as I tried to bolt in the new used ecu it died again and wouldn't restart. I was following your saga hopeing to find some clues and checking the internet. I was set to check the ads relay but found I didn't have one that year ! This morning I unbolted all the grounds I could find and used a course sandpaper to clean them, I also used some new clean washers when I bolted them back together. I also noticed the vacumm lines looked loose to the map sensor so I went and got new vacumm hoses and replaced all the line. The truck started right up and ran fine , I took several trial runs around the block and it was fine and it ran perfect when I floored it. I still had the ecu out so I checked the output voltages to the cps and found everything to be fine. I used the original ecu and drove it home without issue !!!!!I thought the grounds looked fine before nothing loose etc but I think it's fixed hope this helped and good luck.

Mine did the same thing and it turned out to be two things. First the battery which was in it was too small and when cranking it alot it got down to 8 volts . The second was the crank sensor wire was rubbing the exhaust manifold when I wire tied it out of the way it started fine . I also had a problem with the wire harness that ran ontop of the intake to the injectors , you could move it and get some of the injectors to not fire. hope that helps