cold stalling problem

I'm having a very irritating stalling problem with my 1990 buick lesabre. When the engine is cold, if i dont let the car sit and warm up for at least 1 minute before shifting into gear the engine will sputter and stall. If i hit the gas quickly enough when it starts to sputter, i can sometimes keep it running. I get absolutely no problem if the car is warmed up for at least a minute and the problem gets worse as the outside temperature decreases (in the summer i may just get a little sputter but no stall). Within the last year i have changed the idle air control valve, plugs and wires, O2 senson, egr valve and coolant temp sensor but the problem still persists. I tried searching the lesabre forums but had no luck in finding the solution. I was thinking it could be the coil pack, but i have no miss or hesitation at a high RPM leading me to believe the coils are working properly. could it be a problem with the ECM?

Well...I would just let it warm up....but that's just me...
Try, (maybe), resetting the ECU, and see what happens. I'm not saying it's a magical fix-all, but it certainly wouldn't hurt anything. All you have to do is disconnect the battery for at least 10 seconds, by just removing one of the cables from the terminals on the battery.
If that doesn't work......maybe check your tranny fluid. I know it's a longshot, but just try it. Don't ask why, I just have a hunch...
And if that doesn't work...I don't know.

I normally do just let it warm up, but its just irritating when i'm in a hurry and don't have time to sit there. Plus just the fact that it shouldn't be doing that bothers me was well. I don't like it when things are working as they should be. I don't have the car with me right now, it's back home in illinois. I'll be going back there in 2 weeks so i'll try resetting the ECU and checking the tranny fluid and let ya know what happens.

Have you cleaned the throttle plate? Also, is the ECU using the MAF sensor data or has the PROM been changed to use MAP data (assuming GM had a PROM for this car and it has MAF)? More info is needed if you have it...even little details.

I ran a can of seafoam through the throttle body to clean the plate and intake. My acceleration got a lot stronger, but the problem did not go away. There is a MAF on the car. I don't know if the ECU uses its input when the motor is cold though.

Is the MAF sensor in the hose going to the throttle body? If it's in-line, the MAF sensor is just one of several items that could cause your stalling issue, but there is a free test. With the car idling, take a screwdriver (medium sized) and tap the MAF sensor with the handle. Not very hard, kind of like tapping on the glass to get someone's attention. If the engine stalls, sputters or in any way 'reacts' to the tap it's bad. Do it several times to be sure. GM's early in-line sensors had major problems. So many in fact, that they started releasing PROMs that used the MAP sensor instead of the MAF sensor. If your's is found to be bad, I'd check for the PROM rather than replace the sensor. I would also check your fuel pressure from key-on to final running. Just something to look into. Keep us updated.

Um....not to offend....but I'm confused by your suggestion.
How, exactly, would tapping on the MAF sensor do anything? Besides breaking the wire, I mean.
Unless, of course, you're referring to the "flapper box" MAF sensor, in which case, I'm still confused...
I'm REALLY trying not to sound mean, I'm just wondering.

No offense taken. Light tapping will not break the wire and I don't kow of GM using a flapper-style MAF (Toyota re-brands excluded). The early GM MAF sensors, the large plastic ones, failed internally and vibration would cause them to intermittently malfunction. This caused a stall or miss when tapped. I finally found a site that shows the LeSabre MAF for 1990 though (sites were blocked at work, but I'm home now) and it is probably not that type of sensor (they changed styles right at '90). So, it's likely not the problem. RACIN: I would still check fuel pressure, but suggest cleaning the throttle plate and body by hand (both sides of the plate all-around the edges, and the body). You may want to clean the IAC pintle also. You could still tap on the MAF, but the bolt-on ones are pretty reliable.