I put a used engine in my 2000 cherokee with 4.0/aw4, and it is still doing the same exact thing as the old engine. I bought the jeep with a blown engine, didn't even try to start it until I had it home and off the trailer. I started it up and drove 100 feet and it sputtered, died, then started knocking when I started it back up. I got it back inside and pulled the motor. It did have bad scoring on cylinder #2.
Fast forward to the new used engine. Fired it up, ran perfect, great oil pressure, held temperature, so I put it in drive and drove 100 feet. It sputtered and died. When restarted it started knocking. deja vu. When it knocks it runs really rough. Then the knock goes away. It's bad enough that I don't want to run it any more until I figure it out.
Here's what I know:
-New crank sensor
-cam sensor is aligned properly
-wiring harness looks good
-fuel pressure and spray pattern is good
-oil pressure is perfect
-torque converter bolts are tight and flexplate was inspected for cracks(it is the flexplate from the 2000 motor)
-put new plugs in after knocking, old ones all looked good
Anybody have suggestions?
Fast forward to the new used engine. Fired it up, ran perfect, great oil pressure, held temperature, so I put it in drive and drove 100 feet. It sputtered and died. When restarted it started knocking. deja vu. When it knocks it runs really rough. Then the knock goes away. It's bad enough that I don't want to run it any more until I figure it out.
Here's what I know:
-New crank sensor
-cam sensor is aligned properly
-wiring harness looks good
-fuel pressure and spray pattern is good
-oil pressure is perfect
-torque converter bolts are tight and flexplate was inspected for cracks(it is the flexplate from the 2000 motor)
-put new plugs in after knocking, old ones all looked good
Anybody have suggestions?