Oldsmobile/Buick Repair: Misfiring with engine warm and accelerating, throttle position sensor, buick regal

Question
I have a 1990 Buick Regal with a problem i cannot figure out.  when the weather is cold (winter) car runs fine day/night. in summer time though when it starts to get warm.  the car runs fine when you first start it.  after you run it and the internal temp comes up, it starts to buck and shake when you try to give it gas.  when it idles (and it idles fine) it's great.  you give it a little bit of gas and it starts to buck.

Answer
Throttle position sensor can cause a hesitation during acceleration, when warm, but it isn't used when the engine is cold, so there is a possibility.
Mass airflow is another. Read this article,(Ford, but they work the same, and this is a good article).

http://www.fordscorpio.co.uk/cleanmaf.htm

Check the EGR valve, and see if it happens to be opening during the problem. I would unhook it, just for the test.

Van