300ZX JDM TT won't start

Discussion in 'Z32 Technical' started by SuperZ, Feb 7, 2019.

  1. SuperZ

    SuperZ Resident Z lunatic

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    92 Auto JDM TT 2+2 ..... Engine is back together after .....

    fitting with GT2860RS TT's and converting Auto to Manual Gearbox with wiring specialities auto to 5 speed conversion harness

    Engine is also fitted 800cc SARDs and Nistune Chip fitted - used the 92 AT base image and then adjusted the Injector value from 370cc to 800cc

    Engine turns over fine ...but no sign of starting
    Fuel pressure tests reveal no loss on rail and the regulator holds steady at 43.4 PSI
    Diagnostic Lights indicate both spark at Coil Pack and Injectors are firing (New Injectors) when turning over

    Engine turns over great ..... just doesn't fire... or even stutter... despite electrically working correctly and having air / fuel....

    I can only think I have incorrectly set Nistune ....and the the injector K value is somehow so far out ... and its flooding the spark....? Or I have huge vacuum leak that is not apparent .... (Thoughts)

    How else can it not fire, stumble or stutter ..... if its firing coilpacks, injectors, has air and has fuel pressure

    TPS is at .48V

    Detonation Sensor is the only Code that has activated despite not starting - it is the only Code given but it will not stop the engine from operating

    Auto to Manual wiring conversions only affect starting circuitry - so if the engine starter works, it means the circuit is working correctly and cannot be related to it not starting (i.e. inhibitor / neutral switch is connected properly etc)

    Thoughts ?
     
  2. MagicMike

    MagicMike Mod and Event Coord [QLD] Staff Member

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    Have you tried switching it off and then back on again?
     
  3. MagicMike

    MagicMike Mod and Event Coord [QLD] Staff Member

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    Check base timing, confirm that all the injectors and coilpacks are actually firing in the correct order.

    Been issues with the wiring specialties harnesses not being 100% reliable in their numberings.
     
  4. MagicMike

    MagicMike Mod and Event Coord [QLD] Staff Member

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    Pull the plugs and check for wetness.

    Don't rely on the test lights to confirm spark. Actually eyeball the spark so you can gauge strength.
     
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  5. SuperZ

    SuperZ Resident Z lunatic

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    The wiring specialities harness was only for the AT to Manual gearbox conversion ... still have original injector wiring attached to the SARD style connectors, so the order will be correct ...checking the base timing and eyeballing spark / checking for wetness sounds like a good next step .... will do that and see how I go (and report back) ... Cheers Mike...
     
  6. Martin Williams

    Martin Williams Active Member

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    You have been playing with the wiring around relay box in engine bay on passenger side. check that the Ignition relay is operating and no wires have been disturbed or damaged. I had exactly your symptoms after major work.
     

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