Chevrolet Repair: Engine Fuel Supply and Power, fuel pressure gauge, engine rpms

Question
My '94 Silverado 4x4 xcab auto tranny 5.7L v8 w/FI has been experiencing intermittent fuel supply problems (I think). When driving, there has been an occasional jerk in the drive train as though the engine has lost then regained power. This mostly happened under heavier than average load. Driving in reduced gear minimized the problem. Recently, the problem has resulted in a general shimmying and fluctuation in engine RPMs and geatly reduced  power. I suspect the fuel pump; however, I'm not sure which one. What's the best way to trouble shoot this or should I just take it into a qualified repair shop? The only past problem that I've experienced has been a rare shutdown of the engine following a strong left turn when accellerating from a stop. Under those circumstances, waiting a few minutes, the engine restarts and runs normally.

Answer
Hello Tom,
Unless you have two tanks, you only have one pump.
If I were checking fuel problems, I would connect a fuel pressure gauge as close to the engine as possible, meaning between the filter and engine. Connect it where it can be watched while driving, and then go make it do it.
If the pressure remains up around 14 PSI, it isn't the pump.
If the pressure drops with the stumble, then work toward the pump, connections, etc.
But there are other possibilities.
The EGR valve could be opening, or a spark problem could be the culprit. A borderline plug or plug wire could shunt the spark to ground in the wrong place when under heavy load, and that would jerk more than a fuel problem.
Van