Stalling when I let up on gas pedal

Hi, I've got a 1994 BUICK PARK AVENUE V6-3800 3.8L, and it's stalling on me pretty frequently. The car seems to idle and accelerate fine. However, if I use the gas pedal, then once I take my foot off the pedal, the engine stalls. If I let it up slowly and carefully, or if I'm just driving slower, sometimes it won't stall, but the rpms will drop low and the lights will dim for a second before they go back up.

I've checked my PCV valve, replaced my spark plugs, and used some wire dryer, fuel line cleaner and gasline antifreeze.

At this point I took it to a mechanic. They cleaned the throttle body and mass air flow sensor. Didn't help, so I brought it back. They replaced the IAC motor. Still didn't do anything.

Any suggestions? Thanks.

Has anyone checked for vacuum leaks, or the TPS voltage @ closed throttle? Do you have any DTC's?

I'm not too great with cars, so I don't know all the abbreviations, what are DTCs? Can I do any of these things on my own fairly easily?

Looks like it was the IAC motor. The first one they put in was just faulty. Thanks for the suggestions.

Thanks for the feedback! BTW, DTC's (Diagnostic Trouble Codes), or SES (Service Engine Soon), or CEL (Check Engine Light) all are basically the same thing. You should of had one with a bad IAC.

my 94 park ave is doing the same thing. Can you tell me what the IAC motor is? and where is it on the car?

Unplug the Mass air flow sensor. If it stays running, then it's bad.