Last Feb my fuel pump and sending unit went out on my 95 blazer w/ a vortec V-6. They replaced both and about two months later I lostall power and had to drive like 20 mph all the way home from work. I had a friend who is a mechanic look at in his spare time and said that pump was not putting off enough pressure, so I took it back and had that one pulled and a new one put in and 2 months later same thing. This time the pressure was fine, and one night my wife was following me home and my muffler was glowing red, so they replaced it said that should fix it. I had the linkage in my gas pedal and today I tried to replace the fuel pump relay and all I'm getting is rough idle, my rpm's rev up and down all most to the point of the motor shuting off,and somedays it will run fine and others I will lose all power to the point it shuts the motor down and when I start up again it runs fine for a few days. Please someone help me its getting to expensive to handle.

 

When was the last time you repleced the fuel filter? My filter clogged causing lose of power and noises comming from the pump. After I replaced the pumpit ran fine for awile then would have problems starting I could bang on the tank and the pump would come on. So I crawled back under it and found a loose connection going to the pump.To replace the pump you have to drop the tank and it pulls on the connectors just a bit you could have a loose connection.

 

checked all connections and i have had several fuel filters put in over the past year.