300ZX TT Won't Rev

Discussion in 'Technical' started by Terry, Jul 28, 2018.

  1. Terry

    Terry New Member

    Ok,
    I just got a 1989 300ZX TT, problem is it will start an idle but won't rev? Has good fuel pressure and plugs at new etc the MAF seems to be all good. Any ideas on what it could be?
    Thanks
     
  2. East Coast Z

    East Coast Z Well-Known Member

    When you say "I just got a 1989 300ZX TT".,,,,,,,,,,,,,,

    Has this problem been evident from the moment you got it?
    Or, has it been going OK & now the problem has arisen?

    Have you checked the engine compression?
    Have you checked for logged fault codes?

    What is the "good fuel pressure" reading?
     
  3. scottyoz1962

    scottyoz1962 Active Member

    Check the tps, make sure the throttle cable isn't caught on the t-body, run a diagnostics check for fault codes. And then take it from there.
     
  4. Terry

    Terry New Member

    I was thinking the TPS? Will do a fault code anyone know where plug is located? Compression is good and the fuel pressure is 45psi. Car was not running when I got it last owner lost interest in it. He reckons it needed new injectors not so sure about that atm.
     
  5. East Coast Z

    East Coast Z Well-Known Member

    The DDL is located near the bonnet release under the dash.
    45psi sounds about right, specs indicate 43.5psi.
    What are the compression numbers for each cylinder?
     
  6. zx299

    zx299 Well-Known Member

    As others have said …… check for fault codes. If it won't rev above approx. 2500rpm it will be the AFM, but if it fails to rev cleanly, then check your ptu.

    Fault finding on a zed is a process of elimination. More than likely, you'll find you have a number of faults (especially on a project that somebody else has abandoned). Be persistent, each step will get you closer to a smooth running zed :cool:

    When you get the sh@ts with it (and you will), walk away and come back to it at a later date. You'll get there eventually, bypassing the temptation of the "matches + gallon of petrol"
     
  7. Martin Williams

    Martin Williams Well-Known Member

    Great reply!! Problems like this are more easily solved if you have all right equipment, spare AFM/TPR/PTU etc and assistance from this forum
     
  8. Terry

    Terry New Member

    Ok,
    Went to do a diagnostics today and when the car started to idle. I noticed that one of the coils was getting hot and starting to smoke, so I shut it down and replaced it with another and the same thing happened again?? I then started it on just 5 coils and all good no smoke from the others? Any ideas? I didn't do the diagnostics as it was only running on 5 cylinders.
     
  9. rob260

    rob260 Administrator Staff Member

    Sounds like you have a dead short somewhere
     

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