What is causing yo 1990 Chevy Silverado 3500 to buck at cruising speed

robert1987robert1987 Member Posts: 1
edited January 2018 in Chevrolet
I have changed the ERG, fuel pump, distributor and cap, plugs and wires, mass air flow sesnsor, coolant sensor already and nothing fixes it.


  • 0patience0patience Member Posts: 1,712
    edited March 2018
    Fuel pressure regulator is a good possibility.
    Disconnect the vacuum hose and see if it is wet with fuel or smells of fuel.
    If it is, the diaphragm is blown.

    That is assuming, of course, that all of the ignition (timing, etc) and fuel filter have been checked or replaced.
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