You Probably Don't have enough refrigerant in the system. they sell R-134A cans at your local auto parts store for about $20 DO NOT OVERFILL IT.
why does my 1991 Chevy lumina that when going up a hill or when it reaches approximatly 65 mph starts hestitating, when cars get older they do that.
If you know the value of the resistor you can cut the wires going to the lock cylinder and solder in a resistor of the correct value.
If the pump is leaking or noisy then assume it is failing.
Gravity. The car is heavy and doesnt want to move, so you must excelerate to make the car go uphill. If a car is going downhill, the is no need to excelerate because gravity is pulling the car downhill.
i have a 97 lumina the tranny slips form 2 to 3rd or when you try to go faster is there bands that can just be adjusted???????? or if the tranny going out
Check your fuses
I'm going to bet they are drum style brakes. I have a 1999 Luminia, and they are drums on it.
No the can go faster downhill or uphill
It requires extra power to go uphill, against the pull of gravity.
Fuel filter may be plugged. Catalytic converter may be plugged. Engine may be in need of a tune up.
downshift
The relay is sticking or the horn button on the steering wheel is going bad. Most likely it is the horn button.