93 Ranger engine change now bad miss and occasional backfire

[blair683]

Hi, I have a 93 ranger with the 4.0, 5 speed, 4x4. My original engine started making a bad rattle noise (cam bearings or wrist pin). So I picked up a good running used 4.0 out of a 95 ranger. I swapped the engines the other day the harness and sensors all look to be the same. I used the harness that came on the 95 4.0 and it plugged right into the chassis plugs on my 93 ranger. The engine fires right up and idles pretty good. When you take off though it misses pretty bad and sometimes pops through the exhaust. Some times the miss is pretty bad other times it's barley noticeable. I used the upper intake off my original engine everything else on the 95 engine is what came on it. I also switched out the coil pack from the 95 and put my original coil pack on. Is there any sensors on this 95 that are different from my original 93? Any help is greatly appreciated. Thanks.

 

[knuckleduster271]

Hi, I have a 93 ranger with the 4.0, 5 speed, 4x4. My original engine started making a bad rattle noise (cam bearings or wrist pin). So I picked up a good running used 4.0 out of a 95 ranger. I swapped the engines the other day the harness and sensors all look to be the same. I used the harness that came on the 95 4.0 and it plugged right into the chassis plugs on my 93 ranger. The engine fires right up and idles pretty good. When you take off though it misses pretty bad and sometimes pops through the exhaust. Some times the miss is pretty bad other times it's barley noticeable. I used the upper intake off my original engine everything else on the 95 engine is what came on it. I also switched out the coil pack from the 95 and put my original coil pack on. Is there any sensors on this 95 that are different from my original 93? Any help is greatly appreciated. Thanks.

Make sure you didn't get your oxygen sensor harnesses mismatched. It will cause a random multi misfire