Chevrolet Repair: 1991 Chevrolet lumina 3.1, fuel pressure gauge, 1991 chevrolet lumina

Question
Starts and runs good for a few minutes then starts putting and barely wants to run. Had fuel filter changed (it was really dirty). Better for a couple days and now back to as bad as before. What's wrong?

Answer
GOOD MORNING TERESA,WELL THIS IS A HARD QUESTION,BECAUSE WE DO NOT KNOW IF THIS ENG HAS A FUEL OR IGNITION PROBLEM. AFTER THE ENG STOPS, OPEN THE HOOD AND LOOK FOR THE SHRADER VALVE MOUNTED ON THE FUEL RAIL NEXT TO THE INTAKE SYSTEM.[LONG ROUND TUBE 10 INCHES LONG]  THIS SHARDER VALVE WILL LOOK LOOK A TIRE VALVE STEM WITH A CAP ON IT.REMOVE THE CAP AND PUSH DOWN ON THE SHARDER VALVE TO SEE IF THERE IS ANY FUEL IN THE FUEL RAIL..IF NO FUEL MORE THEN LIKELY THE FUEL PUMP IS BAD. YOU PROBABLY DO NOT HAVE A FUEL PRESSURE GAUGE DO YOU ???? IF THERE IS NO FUEL PRESSURE TO THIS VALVE HAVE SOMEONE CRANK THE ENG OVER WHILE [YOU PUSH DOWN] ON THIS VALVE,ALL THE WHILE THE ENG IS CRANKING OVER THERE SHOULD BE FUEL COMING OUT OF THIS VALVE NOT JUST ON THE FIRST CRANK UP THE ENTIRE TIME..IF THERE IS FUEL THEN WE CAN RULE OUT THE FUEL PUMP..LET ME KNOW HOW YOU MAKE OUT AND WE WILL GO ON FROM HERE.GOOD LUCK,,, TOM..