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Coolant problems and missfire

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  • Coolant problems and missfire

    Hello… I just bought an 86 300zx n/a..and Im having a problem with it missing (or something sounding like a miss) at around 1800 rmp on up.. but only when its warmed up, cold it runs fine.. Also coolant is all backing up into the overflow.. but I’m quite sure its not compression (bad head gasket) pushing it out cause it never bubbles…now It does need a new radiator cause it leaks Alot… so im wondering if the coolent temp sensor is not getting a good reading and goofing stuff up.. just wondering if anybody had any ideas..Also, is there a data link connector anywhere to hook up a scanner to?? Or does the ecu blink?? How can I pull codes??

    Thanks in advance

  • #2
    Well the common answer would probably be the CHTS (cylinder head temp sensor) causing your rpm issue but it could be other items as well.

    First things first. Get a Haynes Manual and download the FSM.

    Both of those books will be invaluable to you.
    Just stand back and throw money.
    Performance costs money.
    Reliable performance costs more.


    • #3
      Sounds like that car needs some work. FSM is the only thing I use. Run the codes (there is no data connector) and fix the leaks. If you replace the rad, get a dual row turbo rad.
      Chuck Stong
      300+ Parts and Performance owner
      2002 ZCOT president and always active member