My 1995 Bonneville would die out on extremely hot days. It would not stall but would not accelerate, it would go at low RPM'* and buck a little bit. It acted like it was not getting gas but fuel pressure checked out fine and the temperature gauge was a little high but the Supercharged engine always runs a little hot unless cruising on highway. I has told by a garage person that something in the catalytic converter could expand on extremely hot days and restrict flow.
Although if I would let the car cool down then it would run OK until the engine temp got hot again, but this would only happen on 90+ degree days