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  1. #1

    Default 1997 Sierra 5.0 shakes, loss of power

    I have a 1997 GMC Sierra 5.0 with 132k miles. It shakes (drastically more when accelerating) and its throwing a p0300 and p0327 codes. has a new fuel pump and filter. any ideas on what could be causing this?

    Thanks in advance!

  2. #2
    Jr. Mechanic
    Join Date
    Apr 2013
    Location
    East Central Iowa
    Posts
    88

    Default

    Here ya go. PO300 random cylinder misfire.PO327 Knock sensor low voltage code. Check wire gong to sensor or sensor itself. The PCM uses the knock sensor to detect engine ping or detonation and adjust ignition timing to compensate. Never seen one cause violent shaking on acceleration. Maybe dropping a cylinder. Just a thought.

  3. #3

    Default

    Update! replaced all the spark plugs and most of the shaking is gone. it idles very low (500-900) now and dies unless you give it some gas.
    With what you just said, I think the timing is off because of this mishap. Will check the wire right now.

  4. #4
    Jr. Mechanic
    Join Date
    Apr 2013
    Location
    East Central Iowa
    Posts
    88

    Default

    Were the plugs pretty fouled up?

  5. #5

  6. #6
    Jr. Mechanic
    Join Date
    Apr 2013
    Location
    East Central Iowa
    Posts
    88

    Default

    May not hurt to do a compression check.

  7. #7

    Default

    Sorry for the delay,
    I don't have access to a compression tester. But today I will be replacing the dizzy cap and rotor, ignition wires, and knock sensor.

    - - - Updated - - -

    Replacing all those still didn't fix my problem.

  8. #8

    Default

    I replaced the knock sensor connector, and now my only problem is the p0300 - random misfire

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