This guy I know...

[Degausser]

A friend of mine... replaced his flexplate without disconnecting his negative battery cable and now his Jeep runs really rough. What should he do?

 

[336wheeler]

Try resetting the computer, maybe. Take off both battery cables and see what that does? Best thing I can think of. I guess it could be flashed, or maybe disconnect the CPS. I don't know... weird problem.

 

[mmcj7]

Replacing the flex plate does't have anything to do with the motor running rough unless he shorted the starter out against the frame. What year and model is the 4X4? He probably pulled something loose and hasn't reconnected it. I would start by checking vacuum lines to the tranny and around the fire wall at the back of the motor. my .02

 

[rattlecanpaint]

Does the flex plate have the reluctor wheel for the crank sensor? Possibly hit the crank sensor and damaged it?

 

[Degausser]

I moved the CPS and laid it to the side before the transmission was taken out

 

[transman731]

a bent flywheel could cause this. did it have a shim for the flywheel?
i have seen the shim on the wrong side of the flywheel cause run issues.

 

[Degausser]

Do you mean the one circular piece that goes towards the back of the vehicle on the flexplate?