ZZ4 Hydr cam Vlave Adj. Problems

Discussion in 'Troubleshooting & Diagnosis' started by mcdevin1973, Jul 27, 2007.

  1. mcdevin1973

    mcdevin1973 Member

    Dec 5, 2005

    So I was hearing some clicking from the vale train and I decided to adjust the valves when the engine was running. I did the whole start the engine, lossen the rocker until it starts clicking, tighten it util it stops clicking and then turn it 1/4 to 1/2 of a turn.

    My problem is now under acceleration the car start popping and dying. I also turned up the idle screw just a 1/4 turn.

    The car didn't do this before I adjusted the idle screw and the valves? Did I do it wrong? Why would the car die while driving on the freeway or under hard acceleration?
  2. blades67

    blades67 Veteran Member Lifetime Gold Member

    Oct 22, 2005
    Chandler, Arizona, USA
    Adjust the valves with the engine off using the IO/EC method.
  3. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    Jun 22, 2003
    Endicott, NY
    First, the engine should be warmed up before adjusting them. Then adjust the valves with the engine running. Loosen the valve to be adjusted up slowly till it just barely ticks. Then slowly tighten it till it just barely stops ticking and wait ten seconds. Then slowly tighten it one quarter turn and wait another ten seconds. Repeat till you get a total number of turns till it's either 1/2 turn total (for a racing engine) or 3/4 turn for a street engine.

    The I/O method really only works well with initial adjustment and works better on solid lifters than it does on hydraulic lifters.

    As for the backfiring, it could be a number of things: spark plugs, plug wires, broken cap, borken rotor, broken valve spring, intake vacuum leak. My money is on spark plugs.

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