On my 97 2500 454 sometimes it runs great but later on I run it again and it starts up fine but when I push on the gas peddle it tries to die out but once I let off the gas it goes back to ideling fine.. could this be a gas line problem or a fuel pump problem

SOURCE: 1995 Chevy silverado with a

I have experienced this problem on similar vehicles. You should try and replace the coolant temp sensor. If it is not reading the correct temp to the ecm, it will not get the right fuel map. Also, the cts will not always throw a code.

SOURCE: 2000 blazer 4.3 hard to start (fuel problem)

Do you have the fuel tester hooked the in the overgrown air valve on the fuel rail in the back of the engine? Or do you have the fuel line unhooked in the back and hooked to the pressure pump? You want the fuel pressure to be in that 60 lb range so if you are hooked into the pressure valve on the fuel rail allowing fuel to go through, then I am betting it is the fuel pressure regulator. To get to that, you have to take the throttle body off and take the plastic plenum that covers the injector packs. On the back of the mount where your six pack of injectors are sits the pressure regulator. If it is faulty then it is dumping fuel instead of holding the pressure like it should.
Get a Chilton or Clymer manual and it shows you in pretty good detail how to fix it. I've done it to my 98 S10 with the same engine.

If you unhooked the fuel line so you are losing pressure from the line back to the pump then I would say your pump is letting fuel back to the tank when it shuts off. My money is on the first possibility though.

Good luck

Dar

• 2007 Answers
• Posted on May 13, 2009

SOURCE: CAR WILL START AND RUN FOR A FEW SECONDS THEN DIES

Mass air flow sensor.