1994 Buick Leasbre chuggs when accelerating when hot outside

Hello,

I have a 1994 Buick Lasabre V6 3800 with 152,000 miles. When it is warm out 90 and above the car chuggs after driving for awhile 25-50 miles. I checked fuel pressure at fuel rail. It is 35-38. No codes are showing. Any ideas?
Thank you.
Larry

I had a similar problem. My LeSabre surged after driving a while, only in hot weather. The problem was corrected by replacing the map sensor. The original map sensor had the car thinking it was at an extremely incorrect altitude.