Hey y’all! My XJ had a cracked piston skirt that turned into a broken piston skirt that turned into a grenade. It's a 2000 w a 4.0. Original motor had 215k before it shot a piston through the side of it. New one has around 70k.
My buddy and I replaced the motor, everything was connected and it started fine, but it was trying to idle at 3500-4k and I immediately shut it off. It had 2 engine codes for a general PCM fault bank 1 and 2.
We tore it down to just the minimum needed connections to start, replaced the intake manifold gasket, and went through all the hoses and made sure they were connected properly or at least blocked off so there were no leaks. I also made sure the throttle cable had slack and that nothing was over-tightened or caught around it.
I go back out there and do a manual PCM reset with the battery cables and everything because l'm thinking maybe the computer reset didn't work, and that's the only thing I haven't done.
Tried to start it, it wouldn't even crank. We had it attached to a big jump box so it had good power, and it just wouldn't do anything. We tried it in neutral, tapping the starter, taking out the fuel pump relay so it would at least crank, and nothing. We swapped the starter and fuel pump relay to see if it was a bad relay and that didn't work either. My buddy heard a weird sequential sounding clicking noise and it was my AC compressor, even though my AC was off in the car.
We pulled that fuse with the others still in and it started fine, still incredibly high revving and he shut it off immediately as well. He said it looked to get up to around 3k before he cut it.
The only thing I can think of is a voltage issue, but even that idea I can't really wrap my head around right. Or this is the 1 in 1000 that actually needs a new PCM.
Do any of y'all have ANY ideas? I'm at the point where I will try anything to get this damn thing running right again.
Thank you so much!
My buddy and I replaced the motor, everything was connected and it started fine, but it was trying to idle at 3500-4k and I immediately shut it off. It had 2 engine codes for a general PCM fault bank 1 and 2.
We tore it down to just the minimum needed connections to start, replaced the intake manifold gasket, and went through all the hoses and made sure they were connected properly or at least blocked off so there were no leaks. I also made sure the throttle cable had slack and that nothing was over-tightened or caught around it.
I go back out there and do a manual PCM reset with the battery cables and everything because l'm thinking maybe the computer reset didn't work, and that's the only thing I haven't done.
Tried to start it, it wouldn't even crank. We had it attached to a big jump box so it had good power, and it just wouldn't do anything. We tried it in neutral, tapping the starter, taking out the fuel pump relay so it would at least crank, and nothing. We swapped the starter and fuel pump relay to see if it was a bad relay and that didn't work either. My buddy heard a weird sequential sounding clicking noise and it was my AC compressor, even though my AC was off in the car.
We pulled that fuse with the others still in and it started fine, still incredibly high revving and he shut it off immediately as well. He said it looked to get up to around 3k before he cut it.
The only thing I can think of is a voltage issue, but even that idea I can't really wrap my head around right. Or this is the 1 in 1000 that actually needs a new PCM.
Do any of y'all have ANY ideas? I'm at the point where I will try anything to get this damn thing running right again.
Thank you so much!