Hi all. I have a '90 Sunbird 2.0L with a 3 speed auto that stalls out frequently when I come to stops or low speeds. Sometimes it even stalls out when I pull out of the driveway in the morning. I recently had a 2.0L with 60k miles on it professionally swapped in place of the original that had 200k miles. The problem continued even after the new engine was swapped in it. I've replaced the distributor, the control module, and all the plug wires, so I'm starting to think it is not an engine problem and possibly a transmission problem since the problem persists. The car starts up every time when it stalls out. The engine usually dogs at low speeds, but then suddenly it will go back to normal RPMs and drives fine.

Any help would be appreciated.

Not 100% familiar with that transmission - but I know my 4T40E caused similar issues before I lost reverse gear, I just popped it in neutral every time I had to stop. Perhaps that can be your test.

If its not trans related, I would check all of your vacuum lines.

Will the car start up right after???? Or do u need to keep revving it to keep it running?? If so check ur Idle Air Control Valve. It could also be a torque convertor locking up and not disengauging. But before you deem ur tranny bad, look into that. Just remove it from the throttle body, and see if when u put the car in gear and such if it still stalls, if so thats not the issue, if not, thats the problem and replace as needed. Goodluck.

Where is the Idle Air Control Valve located? I have a shop manual for the car, but I'm not sure what that would fall under.

The car seems to be getting progressively worse. Today it stalled out in my driveway and I had to keep my foot to the floor to keep it from stalling out, but once I got it going it idled fine the rest of the way up the drive. I'm pretty sure it's the Idle Air Control Valve and I'd like to get this fixed asap.

Thanks for the help so far.

It shold be located in ur throttle body, usually held in with two screws or inverted torx head screws. You can pull it out, and see if the car runs better without it. It will idle higher then normal but thats okay. See if it stalls out anymore, if not, then there is ur problem, if so, then thats not the issue.

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Transmission-Control-Solenoid-BWD_18480536-P_838_R%7CGRPSESWAMS_560539630___ This is the TCC switch better known as the torque convertor solenoid.Sounds to me like this is more your issue than the IAC.To verify this simply disconnect it and drive your ride and see if the problem goes away completely.If it does by having this unplugged will not hurt anything maybe ur mpg at most.Next you need to drain the transmission fluid,change ur filter then replace the switch stated above.Simply the old fluid loses it's ability to reduce heat and wear and fries the switch which inturn can cause the car to stall,drop idle while moving at low speeds backing up or coming to a stop in alot of cases.I would try this 1st over the IAC and if this idea does not fly then consider the option listed in the other post.And the part listed is for your car specificly I selected it based on ur specs not sure if yours is the le but,the eng,and and other stuff should be the mark.

Damn, Ron, I forgot all about that lol Good call

Thanks for the help. I remember I did disconnect the IAC in the last engine which was the problem with the person who previously owned the car. I'm not sure why the IAC would be bad in the new(er) engine, but it's probably a combination of the two (tranny and lump). I'll disconnect the IAC and flush the tranny fluid and see if the problem persists.

Thanks for the link, Ron. I have an LE with the NA L4.