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Fuel issue

Discussion in 'Chevy C/K Truck Forum' started by Bruce2, Aug 21, 2011.

  1. Bruce2

    Bruce2 New Member

    I have a 1988 Chevrolet 3500 with a 454 and when you switch from left tank to right tank truck engine leans out...i have personally changed both pumps ( 1 in each tank) i have changed the switch valve and the switch in the cab, new lines from tanks to switch valve and for the heck of it i just changed the right tank pump again. The reason i know it leaning out cause you can hear the difference in the motor when switching and while watching my scanner i can see block learn(145) going up and the integrator staying low(128) on the right tank and the block learn and integrator matching on the left tank.....any ideas?

    Thanks ...Bruce
  2. Crispyt

    Crispyt New Member

    Not sure if this would have 2 different fuel filters, (one for each tank) but are all the equipted fuel filters new and clean? I belive that between then fuel pump and the sending units on those there is a rubber hose conecting the pump to the SU. Make sure that its not leaking or that it has a hole in it. Or that any possable rubber hoses in the system arn't kinked a little. Do both pumps also have new fuel strainers on them as well?


    Hope this helps a little good luck!
  3. Bruce2

    Bruce2 New Member

    Fuel strainers in both tanks are new..fuel line from tanks to fuel switch valve new, there is 1 filter and its a common filter that is after the fuel switching valve.

    Not sure if computer tied in to fuel tank switch or not...these computers back then where so primitive.
  4. Revredneck

    Revredneck New Member

    I'd take a look at the grounds for the pumps. If one of them is a little loose or dirty, it will affect the pump's ability to work correctly.
    Good Luck and God Bless

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