Lumina stalling and jerking

I have a 1992 Chevy Lumina Euro with 221,000 miles on it.

For some reason, the car has a tendency to cut off when you crank it up and put it in gear. It will crank right back up and sometimes it will cut off again when you put it back in gear. Other times, it will be fine. Also, there are times when I'm driving it, that it will start jerking when I get off the accelerator. When I get back on the accelerator, it will get back in the gear kind of hard but will immediately smooth back out.

I talked to my mechanic and he said that it could either be a vaccum line loose (there is one loose but I don't know where it goes) or the idle air control valve.

Which one do you think it could be or could it be something else?

Those would have been my first guess. Idle stalling issues (especially when cold) are usually due to excessive air in the mixture (lean) and the IAC or a vacuum leak are the most likely suspects. Sounds like you are one of a privleged few who know a good mechanic.

My mechanic has won awards for his work on cars. My dad has known him for the longest. Every since I could remember, if there was a problem with a car that my dad couldn't fix himself (which would be almost major), he would take it to him and he could fix it.

I've had a similar problem for about 2 yrs, that kept getting worse. Digest this and see where it leads. I have a 1992 Lumina APV, 3.8L, 4T60E Auto Trans. 132K miles.

It would start up fine when cold. After it warmed up, it would die on the road. I found that if I waited at the side if the road, it would start again. I flashed the check engine light and found no trouble codes. I suspected spark or fuel, but always had it when I checked it at home. Also, when I got on the freeway in 3rd or 4th gear, the engine/trans would buck and hickup and randomly stall for a split second when the torque converter would lockup (TCC solenoid). I thought I may have more than 1 problem going on.

I removed the ignition module thinking that may be causing the stalling problem and had it tested several times at a local Autozone parts store. It passed every time. No progress on the stalling.

So I switched problems and focused on the bucking. Having read before that sometimes the TCC solenoid goes bad, I inquired at the AutoZone about a TCC for this car. The counter salesman said he did not sell this part and the only part he sold was a vehicle speed switch. He then said "sometimes the motor will stop if this sensor goes bad". I bought it, $45, and installed it. It goes in the tail shaft of the trans. I noticed, when I pulled the old one out, it had a build up of band/clutch debris on the face of the sensor pickup. I installed the new one anyway but the clutch debris accumulated on the pickup face could have been the whole problem with the VSS sensor.

Now the van does not buck and has not stalled for a couple weeks. I would have never guessed this one.