slight surging problem in 89 chevy 305 tbi

Discussion in 'Chevy Truck Forum' started by Diesel_Fan, Oct 16, 2008.

  1. Diesel_Fan

    Diesel_Fan Senior Member

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    my truck will be idling and then it will surge a little bit then idle way down and the surge back up. any clues to this problem, i just changed plugs, air filter and all, i havent changed the wires cap or rotor yet but im curious what this could be, when driving it seems to be right on the money just when im idling in gear or neutral even it does this. thanks alot.
     
  2. stumpuller454

    stumpuller454 Well-Known Member

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    Idle AIR CONTROL will be located on throtle body, near butterflies, try cleaning it first, but it may be a inexpensive part anyways...:)
     
  3. barbermike34

    barbermike34 Senior Member

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    I had the same problem on my 89 Chevy 4x4 and stumppuller is right on the money. I cleaned mine with carb cleaner and it worked for a month or two then i had to buy a new one.
     
  4. leolkfrm

    leolkfrm Full Member

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    also check the egr for closing all the way
     
  5. FaselZ71

    FaselZ71 Senior Member

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    Something I've wondered is what is the point of the EGR I mean it just goes from the air cleaner to the exhaust heatshield!
     
  6. stumpuller454

    stumpuller454 Well-Known Member

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    its to help emissions reduction....its it no way help economy, in fact it probly lessens fuel economy....
     
  7. FaselZ71

    FaselZ71 Senior Member

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    Ok I was just think everybody say check the egr and what not. I don't even have an EGR anymore I'm just running open element
     
  8. stumpuller454

    stumpuller454 Well-Known Member

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    yeah it can cause probs, if its stuck open all the time usually the engine dislikes it untill it warms up....
     
  9. jimbo543

    jimbo543 Senior Member

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    fasel 71 hope this helps.

    EGR = Exhaust Gas Recurculation, egr valve is mounted on the intake that introduces exhaust into the combustion chamber to lesson nox emmisions.

    EFE = Early Fuel Evaporation, a valve on the air cleaner snorkle that directs warm air via tube/hose connected to ehaust manifold when a switch applies vacum to valve.
     
  10. jimbo543

    jimbo543 Senior Member

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    had an 88 w/same deal, removed tbi, cleaned up, removed iac and cleaned (was pretty clean), by the throttle linkage on the front side there is either a small soft plug or small hard plug to adjust throttle, the hard one has be cut out, soft one pries out, turn idle screw IN 1/2 turn and truck should be ok. screw sets minimum air rate.
     

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