2001 Chevy S-10 my engine will not start

2001 CHEVROLET S-10
11,100 MILES • 6 CYL • 4WD • AUTOMATIC
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HARDMANB
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my engine will not start. it has central multiport fuel injection. to determine if it was electrical or fuel related. I put a small amout of gas in the throttle body. It starts that way and will idle but dies when I give it any throttle. I replaced the fuel filter and I can hear the fuel pump run. I checked the fuel pressure and it is low. It should be between 55 and 61 psi when not running and the key on. I have measured between 45 and 55. Typically the 45 to 50. It will hold the pressure so I don't think an injector is leaking. Ive been told it is probably the fuel pump. Is there a way to determine if I have a bad fuel pump or pressure regulater (both are hard to get to). I would like to figure out which one is the issue before removing the tank or air intake plenum (thanks for any help)
May 18, 2009 at 11:05 PM
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MMPRINCE4000
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Remove vacuum line to fuel pressure regulator, if gasoline is present, then FPR diaphram is ruptured and will need to be replaced.

The engine should run with 50psi of fuel pressure.
May 19, 2009 at 7:20 AM
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HARDMANB
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My issue is my truck is a 2001 S-10 with the v6, with the central sequential electronic fuel injection. I said multiport below Sorry. The presure regulator is attached to the fuel meter assembly. To access the vaccum port on the regulator I have to remove the throttle body and the air intake plenum plus brackets etc and the coil. is there a point on the other end of the vaccum hose that is accessible without removing the throttle body and air intake plenum?
May 20, 2009 at 12:02 AM
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HARDMANB
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P.S. the pressure is now 40psi key on not running well below spec. does this point to the fuel pump or pressure regulator. it holds the 40psi
May 20, 2009 at 12:46 AM
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MMPRINCE4000
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Well it could be either one.

If you connect a mechanical pressure gauge to the fuel rail, turn of engine, the pressure should hold pressure for several minutes. If it goes down after pump is off, then FPR or an injector/cold start valve is leaking.

If pressure holds after pump is off, then either the fuel pump/filter or a restriction in the fuel lines.
May 20, 2009 at 8:16 AM
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