Engine Performance problem
1987 Other Buick Models 6 cyl Two Wheel Drive Automatic 50000 miles

My Car When Its Cold It Runs Great, After It Reaches 160 Degree Temp, It Starts To Hesitate.

it is going into closed loop at that temp. This is when O2 startes adj. fuel ratio a slow to respond O2 can cause hesitation. If you can find someone with a old OBDI scaner you can read component info. If O2 is got alot of miles on it a good place to start. Let me know and I'll try and get it running smooth.