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    Sticking Butterflies on 8 Stack Hilborn Injections

    Most of the time you can remedy sticking or hard to close butterflies with this simple solution:

    Remove the butterflies:

    Drill the screw holes out with a  #10 drill bit-  just slightly larger than factory size.

    Take a file or sanding block and flat spot the area where the shaft passes on the edge of the butterfly-  ( Take off about .001” or .002” , not much )

    When reinstalling, ensure that you have some clunk from end to end with the shaft moving forward and backward.

    Lube the shafts up well, and after the engine warms up re adjust the gap against the wall of the injector : .002” for Alcohol  .003” for E-85     .004”  for Gas

    NEVER attempt to adjust the butterfly gap later on to help idle –  that is only accomplished by a barrel valve adjustment and/or a pill change.