Chevrolet Repair: Stalling, chev lumina car, fuel pressure regulator

Question
I have a 1991, Chev Lumina, car,3.1 L engine. When decelerating quickly from hwy speed, the engine is stalling. The problem is not a regular occurence, but seems to come and go.
Runs fine otherwise. Fuel economy is good. 280,000 km on motor.

Answer
There are so many possible sensors and controls on this vehicle that without a SCANNER to physically see what each and every sensor is doing, The possibilities are endless.

the most common faults are:

A residue buildup within the throttle body which needs to be cleaned out as it can cause the throttle plate to not close all the way thus causing the vehicle to stall.

You could have an intermittent weak fuel pump which can cause low fuel pressure and or a weak fuel pressure regulator.

Numerous tests need to be performed before a diagnosis can be made.