'97 5.7L Vortec timing reset question

Discussion in 'GMC Truck Forum' started by jesusdrivesagmc, Oct 27, 2007.

  1. jesusdrivesagmc

    jesusdrivesagmc Full Member

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    I replaced that lower intake manifold gaskets and an exhaust manifold gasket, and am buttoning back up the engine...and I can't the engine to get into the right timing. It runs rough, and when I put a timing light on it, the timing mark on the front pulley doesn't budge when I twist the distributor back and forth or even move the distributor shaft a gear tooth either direction. I put the timing light on each spark plug wire and confirmed that all 8 plugs are firing. It seems to me that the computer is nulifying any adjustments that I make to the distributor. What am I missing here?

    Christian
     
  2. mudseeker

    mudseeker Senior Member

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    if i remember right, turning the dist. on that engine will not effect timing. i think it needs to be done with a programer.
     
  3. NCroadracer

    NCroadracer Senior Member

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    Distributor Installation


    1. [​IMG]
      [​IMG]
      <LI type=1>Bring cylinder number one piston to Top Dead Center (TDC) of compression stroke.
      [​IMG]
      [​IMG]
      <LI type=1>Remove the distributor cap bolts and discard. <LI type=1>Remove the distributor cap.
      [​IMG]
      [​IMG]
      <LI type=1>Install a NEW distributor gasket onto the distributor.
      [​IMG]
      [​IMG]
      <LI type=1>Align the indent hole on the driven gear with the paint mark on the distributor housing. <LI type=1>Ensure that the distributor rotor segment points to the cap hold area.
      [​IMG]
      [​IMG]
      <LI type=1>Align the slotted tang in the oil pump driveshaft with the distributor driveshaft. Rotate the oil pump driveshaft with a screwdriver if necessary. <LI type=1>Align the flat (1) in the distributor housing toward the front of the engine. <LI type=1>Install the distributor and distributor clamp.
      [​IMG]
      [​IMG]
      <LI type=1>Once the distributor is fully seated, align the distributor rotor segment with the number 8 pointer that is cast into the distributor base. <LI type=1>If the distributor rotor segment does not come within a few degrees of the number 8 pointer, the gear mesh between the distributor and camshaft may be off a tooth or more. Repeat the procedure in order to achieve proper alignment.
      [​IMG]
      [​IMG]
      Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
      <LI type=1>Install the distributor clamp bolt.
      Tighten
      Tighten the distributor clamp bolt to 25 N·m (18 lb ft).

      [​IMG]
      [​IMG]
      <LI type=1>Install the distributor cap onto the distributor. <LI type=1>Install the NEW distributor cap bolts. Do not overtighten the NEW distributor cap bolts.
      Tighten
      Tighten the distributor cap bolts to 2.4 N·m (21 lb in).

      [​IMG]
      [​IMG]
    2. Install the ignition coil wire harness.
     
  4. NCroadracer

    NCroadracer Senior Member

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    The timing is self adjusting up to approx +/- 13*...... It (the distributor) has to be installed correctly though or the PCM cannot achieve correct ignition timing throughout the rpm/load range and will set a p1304... (I think that's the code).
     
  5. crabtruck

    crabtruck Senior Member

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    That's the kinda detailed answer that makes folks willing to pay the big money to be here.
    I just hope all our replies don't have to be like that, bar is pretty high. Nice job NC
     
  6. mrjohnwayne

    mrjohnwayne Full Member

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    Are you sure it's +/- 13*. I thought it was +/- 2*
     
  7. NCroadracer

    NCroadracer Senior Member

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    I think its more than that, though the important thing is to achieve a camshaft retard offset of 0* @1000 RPM, and unles the distributor is installed correctly, this will not be possible and a P1345 will set.
     
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  8. mrjohnwayne

    mrjohnwayne Full Member

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    no you are right. I was thinking of the install. it has to be 0* +/- 2*
     
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  9. 436'd skylark

    436'd skylark Senior Member

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    the easiest way to do this is with a scan tool, otherwise you'll probably spend alot of time just guessing, and might get lucky.
     
  10. andrew4

    andrew4 New Member

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    how did you fix this problem
     

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