91 caprice classic air conditioning problem

If I turn on the air conditioner while the engine is running, the engine sputters and turns off. Please help. while the car is running the engine light turns on for awhile then turns off. please help.

hows the belt??

I don't know how the fuel injection setup is, but on the carb version has an adjustable solenoid with a plunger that pushes the throttle open just a little when the a/c is on.

See if you have one of those.

it should be tbi

Right, and I forget if there's a solenoid to bump the throttle up or through some other method.

If it's done with a solenoid, it's either disconnected, shorted/grounded, or just worn out.