another new problem :(

Discussion in 'Z32 Technical' started by Ruki, Jul 30, 2010.

  1. Ruki

    Ruki Ricer

    Messages:
    117
    Likes Received:
    1
    Trophy Points:
    0
    got engine back in all wired up everything where it should be.
    but still wont start. starts and runs for about 10 seconds if i use aero start by spraying inside injectors then firing. so that leads me to thinking it the injectors, check all power to lume and all runing correct volts.

    maybe no fuel or power to injectors, i really think its the injectors

    any help?
     
  2. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    Have you got a series 1 or 2 PTU (power transistor unit -the thing on the divers side timing cover if you didnt already know, is it silver or black?) if there is a fault elsewhere in the ignition system, the ECU will generally cut of the injectors all together. from memory when i was diagnosing this 90 Z32 n/a, they will still do a cold start just with 4 injectors connected, and the chances of every 6 let alone even 3 injectors failing simultaneously is pretty rare.

    also the injectors can be cut by the ECU, but not the spark, which is why it may start to fire after you have put fuel in the system manually.

    the car will still start when the AFM, CTS, IAC is disconnected or faulty (it may enter LIMP mode-rev limit is set to 2500RPM-try going down the highway when its 100km/h and your top speed is 90 :rofl:)

    also check the CAS harness connector, if there is a connection error to that device, the car will fail to start.

    i also would recommend getting some electrical contact cleaner and cleaning those connectors that i mentioned, it wont hurt, just spray and let them sit for a couple minutes to dry

    try that and see if it helps.;)
    Rick.
     
  3. michandy

    michandy Active Member

    Messages:
    2,716
    Likes Received:
    12
    Trophy Points:
    38
    hi

    check your fuel pump fuse or make sure you have the fuel lines on the right way around.
    Andy :cool:
     
  4. Peter Black

    Peter Black Active Member

    Messages:
    3,056
    Likes Received:
    6
    Trophy Points:
    38
    This ^

    And also maybe worth seeing if the fuel pump is working at all (can you hear it buzzing when you first turn the ignition on?) or perhaps pull off the fuel line after the filter to see if there is fuel in it or not.

    Probably worth listening to your injectors with a screwdirver or something against them to see if you can hear them ticking while you are trying to start it too.
     
  5. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    Hey Andy, thanks for that heater core btw, now i got something else to do AFTER i check my neighbours bmw out (u dont have a LHR abs sensor for a 318i?:D).

    I hope all goes well for you two;)
    Rick.
     
  6. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    thought i forgot something, fuel pump. lol.

    and check all the other fuses while your there checking the pump fuse.
     
  7. zed4life (zedcare.com)

    zed4life (zedcare.com) Ω vicarious zedder Ω

    Messages:
    5,485
    Likes Received:
    61
    Trophy Points:
    0
    Lots if ideas already. here's mine. You know the basics, fuel, spark air. If adding accelerant helps starting then fuel related may be the issue. Pull fuel line from fuel reg to return line and check for fuel. ensure engine is cold and have plenty of towels to catch the excess. get someone else to crank it over. should be a strong quirt/stream. If no- then start with the most likely to least likely causes.
    1) CAS wiring plug connection: Run ecu diagnostic- if code 11 comes up-there's your prob
    2) fuel pump control unit-try the earth wire bypass (in tech section)
    3) blocked fuel filter
    4) fuel pump.
     
  8. Ruki

    Ruki Ricer

    Messages:
    117
    Likes Received:
    1
    Trophy Points:
    0
    im sure im getting code 12 and code 34.
    getting no power to fuel injectors. fuel lines on correct, fuel pump working, have spark, reg working with right fuel pressure.

    any more ideas?
     
  9. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    did you re-check the codes after you checked and got those 2 codes? i cant remember but i think once you read the codes, exit the self diagnostics system, it automatically clears the codes. if it does then you will need to try to start the car again for the codes to be re-logged, just in case those codes are old logged ones.

    not sure about the detonation sensors, but even if the MAS is faulty or disconnected i am pretty certain the car will just run in LIMP mode.

    Have you got a injector harness tester, plugs into the injector connector and has a LED that lights up when the connector is given power?
    can you get hold of another ECU to see if that is the cause?

    Rick.
     
  10. Tektrader

    Tektrader Z32 Hoe, service me baby

    Messages:
    10,727
    Likes Received:
    123
    Trophy Points:
    63
    Sounds to me like it has a huge vacuum leak.
     
  11. Ruki

    Ruki Ricer

    Messages:
    117
    Likes Received:
    1
    Trophy Points:
    0
    yep reset and checked codes and those are new codes, 12 amd 34. CAS and Knock sensor, but both check and seem to be fine, so no idea why it wont fire
     
  12. Instamatic

    Instamatic Active Member

    Messages:
    1,449
    Likes Received:
    17
    Trophy Points:
    38
    Busted CAS? Have you tried removing the CAS and spinning the shaft to see if it triggers the injectors? Good opportunity to clean the contacts too.
     
  13. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    11 is CAS sensor, 12 is air flow meter - MAS/MAF, but if it WAS 11 or the CAS sensor then the car will NOT start, i can guarantee you that much, i have had the plug fall off the CAS unit (it was missing the metal retaining tab) while driving and the car will instantly turn off while still moving. make sure there is no corrosion build up (green powder crap) on the plug or the terminals, this is also another common issue i discovered whilst diagnosing.

    you can also do a vague test on the CAS, turn the ignition to ACC (all light active on dash), MARK WHERE THE CAS UNIT IS LOCATED!-this affects the engine timing, remove the 3 retaining bolts (10mm i think) on the CAS unit, then turn the CAS unit's shaft around which ever way you desire (it does not matter) and you should hear the injectors 'tick' in certain positions, the CAS unit has a hall affect sensor inside of it, and when it passes through the set gaps it tells the ECU when to put power to the injectors, turning the CAS while the car is set to ACC simulates its set purpose. make sure you set it back to its original position when you bolt it back on! if there is no 'tick' then check the connector, if it looks good and has no green/white build up on the terminals, then maybe try finding a second hand CAS unit to test.

    they are easy to remove. also there is a 'o' ring seal on the CAS units shaft, if you remove it put a tiny bit of lube on it so it does not get damaged upon reseating.

    try that and let us know how that CAS unit goes.
    Rick.
     
  14. Ruki

    Ruki Ricer

    Messages:
    117
    Likes Received:
    1
    Trophy Points:
    0
    hey guys, a new update, got a auto elec on the problem, lent us a device to measure power in plugs while trying to turn over, ment to light an led every 3 seconds or something and we get no light :(

    auto elec says its most likly my cold start, but i have no idea what that is or how to fix it??

    any advice??
     
  15. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0

    try what i posted above with the CAS unit, then tell us what happens

    i didnt know the 300zx had a cold start injector? and usually a cold start injector is one single injector that goes into the plenum chamber, and is only operated when the car is cold for about 2-3 seconds to richen the mixture.

    [​IMG]

    this is what it looks like when it has been removed.

    [​IMG]
     
  16. Lovic

    Lovic Non-member

    Messages:
    1,485
    Likes Received:
    5
    Trophy Points:
    0
    have you played with the air-flow meter circuit recently?

    I had code 12 and 34 before, turned out it was the afm circuit.
     
  17. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    but they will still start with no MAF connected, tried that when i was diagnosing a z32 before, it had a faulty MAF, but it would still start and run with the plug disconnected, just limits revs to 2500rpm. this is why i am pushing to test the CAS (wont hurt to try that first anywayz). ;)
     
  18. Lovic

    Lovic Non-member

    Messages:
    1,485
    Likes Received:
    5
    Trophy Points:
    0
    my situation was different, i connected the air-flow signal to safc. first few days were fine but one day i couldnt start the car. it removed the safc and the car started again.
    i.e air-flow signal can be the cause.
     
  19. suzzy300zx

    suzzy300zx New Member

    Messages:
    26
    Likes Received:
    0
    Trophy Points:
    0
    hmm strange, one thing is for sure, nissans can be very temperamental. i dunno about messin with AFM settings, but that can be asking for trouble if you dont know what your doing, especially in the long term if the mix is too far one way:eek:

    in your case, it could have also been the O2 sensors that gave the system away? did you end up reconnecting the SAFC system after that? when i googled for the Apexi SAFC wiring to the maf for the z32, there were a couple of different opinions (which is NEVER a good thing).LOL

    but if the situation was a factory car and has not been tampered with on the MAF....
     
  20. stumagoo

    stumagoo Active Member

    Messages:
    2,097
    Likes Received:
    20
    Trophy Points:
    38
    No they don't as far as I know but they do have the AAV which is nerct top the IACV both control idle but the AAV only does so when the engine is cold. This overrides the IACV and its idle settings.

    If you can remove this and check that when cold there is just a small slither of a gap when looking through. There are more involved articles if you search for them on cleaning etc.

    However I know about this valve due to the fact mine failed and was jamed wide open, I was still able to start my car just never able to set my idle once warmed up (was idling very low)
     

Share This Page