I just had my Transmission rebuilt on a 93 Grand Cherokee. Once the Jeep is started the motor starts to shake alot and it hesitates, sort of like its loosing power and after a few seconds its good but the check engine light stays on. The mechanic who rebuilt the transmission says it could be a bad fuel injector or the fuel filter. So I drove it from the shop to my house and all along the way it wouldnt stop shaking.Came home let it cool off turned it back on and same problem. Can anyone please help. Thank you.

You need to access the Engine code or codes. Turn the Ignition key on -off -on -off -0n-off within 5 seconds. Then count the flashes and post back. The trans mech could have knocked something loose or left something unpluged if you didnt have these systoms before.

So its saturday morning, Now the jeep starts and shakes alot an as soon as the check engine light turns on the jeep turns off. I'm taking it back to the transmission shop.

sounds like your crank sensor or cps may not have survived the trans repair.you didn't say if it was a 4.0 or a 5.2 but if it was a 4.0, you have to take the sensor out because it is bolted to the trans case.I have seen older ones go bad after this and I think it somehow damages the wiring coming right off the sensor.if that is the case,it probably is not something the guy that worked on it did.I have seen that happen a couple times on older cars.now if it is a 5.2,then its another story.that sensor stays bolted to the back of the block.the bellhousing has a slot that the sensor fits in.if you are not careful,you can damage the sensor putting the trans in.or the wiring gets caught between the block and the trans but it usually doesnt even start if thats the case.

The jeep is a 4.0. Today in the afternoon tried to moved it and alot of black smoke came out of the tail pipes. Talked to the transmission shop and they said they will fix the problem because they know that the jeep was working fine before they worked on it.