Trans lock up symtoms?

[Glamissand1]

Ive got an 88 cherokee, runs fine in park or neutral. Won't run in gear with any pedal input. 4.0 auto. At one point it wouldnt run at all, but after pump icm and map sensor, it has a loping idle but idles well.

 

[lunghd]

Need some more info than provided...

pump icm?

Have you checked for vacuum leaks? (Especially along the intake/exhaust manifold to head surface.)

Why do you think it has anything to do with the transmission? (Serious question.)

 

[Glamissand1]

Need some more info than provided...

pump icm?

Have you checked for vacuum leaks? (Especially along the intake/exhaust manifold to head surface.)

Why do you think it has anything to do with the transmission? (Serious question.)

New parts, fuel pump, strainer, fuel filter, ICM, coil, wires, plugs, MAP, MAT, CPS, TPS, and all new vacume hoses. There are no air leaks, at least nun that change with leaktest. The IAC is next to change, may just pull and clean and lube. Turns out to be a fix by last owner, all the sensor grounds where soildered together to one wire, which was barely making contact. As soon as a load was put on the motor it would open the grounds. Plus side my cherry got her mustard back. Sry for lack of info.

 

[Jeepjeepers]

Ive got an 88 cherokee, runs fine in park or neutral. Won't run in gear with any pedal input. 4.0 auto. At one point it wouldnt run at all, but after pump icm and map sensor, it has a loping idle but idles well.

My 1988 XJ did the same thing 6 months ago. I ever got a new computer for it. All it was, was the fuel pressure regulator. (its white, under the hood on the drivers side.) it cost me 15 bucks at the jeep dealership. I hope this fixes your problem