1999 JCS Engine Misfires in Reverse

What engine?

I would be looking for a harness that was too close to the exhaust or was really tight I think. When you put it in reverse, the engine moves which could cause a harness to hit the exhaust or be pulled on even, especially if you had a weak engine mount.

Mike

Perhaps a leaking injector? You say it only leaks in reverse?

The injectors have power applied all the time with the key on. The ECM controls the ground to the injectors. Follow the ground wire from the #1 injector back to the ECM. Wire should be White/ Dk Blue. Look for the wiring harness being pinched/chafed when vehicle is put into reverse. The ground wire is most likely being shorted to ground which causes the injector to stay open.

It's a 99 Jeep Cherokee Sport so probably the 4.0

Calr

The engine is a 4.0

The mechanic that replaced the ECM, replaced the White/Blue wire from the socket to the injector back the the socket for the ECM and all is well so far. It's been two weeks and seems to work great.

Thanks for your help.

Phil