My 2001 Silverado will start, but takes 4-5 times of starting to keep it running. Can anyone tell me what the problem is and how to fix it?

SOURCE: Truck has trouble starting- runs fine after start

I found the fuel pressure regulator on the fuel rail was leaking fuel into the intake manifold via the vacuum hose.Was hard to start and rough idle. Pull vacuum line and see if fuel is coming out-if so like me-replace it. About 50.00 at Murrays. Also the two inner cylinders on the passenger side-opposite of the vacuum line will be very rich fouled-replace them all

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

SOURCE: 1999 chevy silverado won't start.

You need to test the fuel pressure with a special gauge, the pressure should be greater then 35PSI. The Vortec set up has more to it but what you seem to be discribing is a faulty fuel pump. Im assuming that the fuel filter was changed too. But you need to have a special tool that will allow you to isolate the fuel flow from the tank to the engine. popular reasons for fuel system failiers are filter, pump, fuel pressure reg. valve(located underneath the plenum) and not common but maybe fuel pump relay.

SOURCE: 1999 chevy silverado 4.3 new

I just replaced the fuel pressure regulator and now I am hearing a vibrating noise from the fuel line under the truck. What do you think the problem is.