Hey to everyone. Long time reader of this forum. I have fixed many of issues on mine and friends jeeps from researching here but first time posting I am just stumped on the current problem I’m having.
98 Cherokee 4.0 automatic
The Jeep was given to me free with no motor. Everything else intact. Was a 1 owner Jeep the lady just wanted it out of her yard. I replaced the motor with one from a 97 grand Cherokee and used the factory wiring harness from my 98 and the XJ accessories. The motor will crank but will not start. I have no power to fuel pump, does not prime when turn key on. Have no spark. And the only gauge that moves is the oil pressure gauge when key is on or cranking. I have held trip button and entire cluster works but I have not seen a CEL, only check gauge light. I have no power to the PCM fuse #11 in the kick panel or no power to fuse 21 and 24 in the PDC. I have 12v to PCM pin on battery+ and 12v from ignition to PCM. I can ground the pin from PCM to fuel pump and squirts fuel out fuel rail instantly. (Have it unhooked at fuel rail) I also have no 5v reference at any sensor. None at all, doesn’t even register my volt meter. I have unplugged every sensor on the Jeep and tried key on with absolutely no change. I have cleaned every ground on the Jeep more than once. Brand new battery. Have tried hooked to jumper cables as well. I can see no wires broken or burned unless deep inside a harness somewhere. All the windows, door locks, radio, lights work. But no gauges no fuel pressure and no spark. What the heck is going on or can I try next? Thank you I really appreciate it sorry for the long post

 

Changed PCM. Problem fixed.