Question about 1996 GMC Sierra

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!996 Chevy pick-up 4.3L CPI Fuel problem

Truck will not start unless I pour gas into intake. Fuel pressure goes to 60 psi while cranking then drops to 0, doesn't hold pressure. Owner has changed fuel pump, filter and pressure regulator. I don't have a manual for this vehicle to properly make any diagnostic checks. I am a retired auto technician, ( retired 1996) and I am not familiar with this CPI system. Trying to help owner who is on hard times. Any help would be appreciated.

Thanks,
Frank
navycwo@bellsouth.net

Posted by on

  • Frank Jun 06, 2009

    Marty,
    Thanks for the reply. If that were the case,I assume that there will be a fuel smell, correct? Is there any way (test) to know for sure if the problem is with the FI spider?

    Thanks,
    Frank

  • Frank Jun 07, 2009

    Pinched off the return line last night, and still had the fuel drop, also fuel pressure is now only 30 psi. Looks like a bad fuel pump.

    Thanks,
    Frank

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Hello, sorry for the bad luck u r having with the 4.3l cpi.........unfortunatly it is common for the "spider legs" to break or crack causing a large fuel leak inside lower plenum... the fuel injection spider is not too expensive or difficult to change, but there is some time involved.. i hope this helps, marty

Posted on May 29, 2009

  • MARTY
    MARTY Jun 07, 2009

    you can try to disonnect or block the fuel return line to see if the pressure drop exists in the lines or the spider. you are correct though! you would smell the fuel through the intake or exhaust,.....definately try to isolate the return line to see if the drop is at engine or at tank,\! marty 541-815-6508 good luck

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