Engine cutout while warming up.

Discussion in 'Technical' started by Masked Goatrider, Mar 11, 2018.

  1. Hi fellow Zedophiles. I have had an intermittent problem since last service of the engine cutting out while driving.

    It occurs while I am off the throttle and braking with clutch fully depressed. This only seems to happen when the vehicle is just at or nearly at operating temperature but can be a little confronting particularly at intersections or roundabouts.

    The fuel pump control unit has been replaced in the last 12 months and seems to be OK. Idle when fully bwarm is 750rpm.

    Should I have the idle taken to 850rpm, flush the injectors or have the FPCU checked? Any other ideas would be appreciated as well.

    The girl is a Z32TT, 1992 with 116000 km the clock.

    Thanks all

    Best regards


  2. DazzaZ32

    DazzaZ32 Active Member

    Sounds like one of the vacuum lines around the wrong way check they all on correct.

    TWIN TERROR Well-Known Member

    Check that the ecu temperature sensor is not faulty ( the 2 wire one) you can check it on ecu talk if you have one. The single wire temperature sensor is just for the gauge. If the ecu temp is reading incorrect the fuel dosage will be off. Also if you changed the plugs some of the coil to spark plug leads have a liitle carbon contact and spring that can fall out when removed (some model do not have this so check them all to see which ones you have. Also check all the connectors - coil - ptu - cas - ec.t for corrosion and clean.
  4. Thank you Dazza and TT.

    I will pass this on to my mechanic at "the little shop of horrors". He is a bit of a Z32 guru and loves the signposts this group so kindly provide.

    I will let you know the outcome.

    Best regards
  5. East Coast Z

    East Coast Z Well-Known Member

    "I will pass this on to my mechanic at "the little shop of horrors". He is a bit of a Z32 guru and loves the signposts this group so kindly provide."

    A Z32 guru?

    1. Check fault codes.
    2. Datalog
    3. Check TPS voltages.
    4. Check fuel pump, NOT the fuel pump control unit.

  6. Thanks East Coast

    He is pretty good - brilliant for NW Tasmania. Has cared for quite a few Z31 and 32s over the years and has a very good grasp of foibles etc. Picked the unupgraded power transistor when it failed and got a loan of a temporary one for me until the upgrade kit arrived. When I need anything done I don't have to take a bank manager with me either!

    Thanks very much for your help as well.

    All the best

  7. AndyMac

    AndyMac Better than you

    Stuck IACV (idle air control valve) or bad connector is a culprit. Basically it's there to ensure there's enough air to maintain idle when the throttle bodies close. The can get gummed up or the solenoid can fry, and the symptom is stalling when coming off the throttle as it's usually stuck in place of maintaining regular idle, however coming down the rev range, there's not enough air to stabilize the idle.

    Once you've checked vacuum hoses and TPS voltage and all ok and it's still happening, the IACV is your next best bet.

    For a quick dirty fix, you can slightly adjust the throttle stops just enough that it almost closes, and it raises your idle about 100-150rpm, but it will stop it happening.

    If you get to this point, you can strip the IACV and clean out the crap with some petrol as long as the solenoid is actually clicking (cross 12 volts across the plug and listen for the click), or you can just look for a second hand one that works.
    pmac likes this.
  8. Thanks Andy
    The Z only does around 2000 km a year and generally around town at low loads and speeds so it could be a buildup of crud. She goes to the Doctor on Monday.
    All the best
  9. Thanks everyone.
    The Z came back this afternoon. The upshot was some replaced vacuum hoses that were skanky, an intercooler hose that had come loose and was sucking outside air and throttle bodies and associated bits full of crud.
    She seems to be running sweetly now and a long run to get her good and hot has been recommended.
    The whole exercise cost me $75 including pickup and delivery. Bargain!
    I very much appreciate the level of knowledge and insight you good people provide.
    Best regards

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