'87 Mj Dies

[jimoshel]

Wanted to see how my latest acquisition runs so I made a run into town with it. 20 miles. Ran great, with one minor problem. Charged down the on ramp and was doing 85 when I hit the highway. Had a slight vibration but that was the old tires on it doing that. Not death wobble. Ran smooth at 75 the rest of the way in. It runs and starts good. Just when ever I let up on the gas it dies. Would start right up again, no problem. Only dies when I'm in 4th or "O". In 1 or 2-3 it doesn't die. Just idles like it's supposed to. Haven't started trouble shooting yet. just looking for some ideas.

1987 MJ

4.0L

Auto with column shift. :dunno:

[Minuit]

Not sure if this would help you in that situation but mine would die and start right back up. Ended up being a bad ignition coil, but if it happens under consistent circumstances I would guess that an intermittently failing sensor. Maybe TPS?

[cruiser54]

Refresh the grounds, clean the C101, refresh all connections, clean the throttle body and IAC. Then, check the TPS adjustment on the engine side connector.

[jimoshel]

All Good suggestions and I will be doing them. However doesn't answer the question. Why only in 4th and not the first 3?

[HOrnbrod]

Well, it's going into O/D so the torque converter lockup solenoid is okay. First thing I'd try is adjusting the throttle valve (TV) cable because it's free and easy to do. If no joy I'd try adjusting or replace the TCU as it can cause shifting problems with the AW4 if going bad.