Confused about spark plug wire order and rotor button position on 350TBI????

Discussion in 'Chevy Truck Forum' started by jmbryant44, Oct 11, 2010.

  1. jmbryant44

    jmbryant44 Member

    Oct 11, 2010
    Likes Received:
    I have a 90 model 350 tbi motor I am about to put in a truck. I bought it from a guy and to my knowledge nothing has been done to it. I have changed all of the wires, cap, and rotor button. The standard 350 diagram shows the number 1 cylinder slot on the distributor cap (looking at it from the front of the motor) at 6:30 on a vaccum advance dist. and 5:30 on an HEI dist. which is what I think I have.

    With no. 1 at TDC the rotor button should be facing 5:30 and then going clockwise correct? The spark plug wires should then be placed in the firing order stamped on the intake going in that clock wise direction.

    What I'm confused about is I have my wires where I feel they should be with the no.1 piston at TDC but my rotor button is pointed to about 11:30 which is where the #3 cylinder should fire. How can this be possible, especially if the distributor has never been removed? Someone help please? I want to figure this out while it easy to get to. Thanks.
  2. 88fivespd

    88fivespd Full Member

    Jan 16, 2008
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    Your crankshaft turns twice for every revolution of the rotor because the rotor is driven off the camshaft. Turn your crankshaft one revolution and the rotor will be pointing at the 5:30 position. It sounds like all is well.

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