Idles rough and dies when put in gear any ideas?

[bufordanthony]

Only in gear huh? Get a manual. Not too up to speed on auto's, but I'm still leaning towards the vacum idea. Found some stuff poking around on the web. Maybe look for leaks, or crappy lines down by the tranny... , or get a manual.
Have you tried putting it in one of the "set" gears? Try putting it in first, and take away the trannies ability to "think". According to the excerpt below, if your truck has one, a bad vacuum modulator could confuse the tranny, and make it not decide on a gear. Beyond that... get a manual.

* The Vacuum Modulator monitors engine vacuum by a rubber vacuum hose which is connected to the engine. Engine vacuum reacts very accurately to engine load with high vacuum produced when the engine is under light load and diminishing down to zero vacuum when the engine is under a heavy load. The modulator is attached to the outside of the transmission case and has a shaft which passes through the case and attaches to the throttle valve in the valve body. When an engine is under a light load or no load, high vacuum acts on the modulator which moves the throttle valve in one direction to allow the transmission to shift early and soft. As the engine load increases, vacuum is diminished which moves the valve in the other direction causing the transmission to shift later and more firmly.

 

[Shran]

I think it's a vacuum leak too - just that there's prerequisites to check first. Sounds like you're doing a good job with those though.

Have you had the codes read? Sometimes a miss (sounds like what you have) won't trip the check engine light, but will still show up when you scan it.

Otherwise...if all your sensors check out good, get out the carb cleaner and start spraying. A good place to start is the plenum gasket between the upper and lower intake manifolds, and the entire vacuum hose that goes from the upper intake to the brake booster. I would check the rubber grommet in the brake booster as well as the vacuum check valve too.

 

[Will]

Can you rev it strongly in park? Does it run like shit when it's in neutral?

How did you discover the injectors were clogged?

It's hard to decipher your meaning. For instance does dying when you put it in gear mean it gently putters away to nothing, or does it mean the converter clutch come son and yanks the engine to a stop in a heartbeat.

We need more feeling here. Get literary on us. You have text only to give us all 5 or 6 senses. Don't spare the keyboard, we really want to help.

 

[AZFX4]

Bumping this because I have the same issue with my 91 and looking for a solution.

 

[doorgunner]

My '89 A/T caused the engine to shutter & stall when placed in gear--the module/switch on the transmission shorted out causing the torque converter lockout to stay engaged...just a suggestion.

 

[AZFX4]

I unplugged the IAC when the engine was idling and there was no difference in the engine. Does that mean its bad?

 

[Shran]

Not necessarily, my experience with bad IAC valves is the engine will either not rev up correctly or it will get "stuck" at high or low RPM.

 

[AZFX4]

Im still curious if the OP ever found the solution to this. I replaced the IAC on my 91 and it runs a bit better but still has no power in gear. I have checked for vacuum leaks several times too. Going to run through the plugs this weekend and see if there is any issue there.