Need help getting stage 3 ca18det to run properly

Thread in 'Other Chat' started by Mgentry90, May 31, 2021.

  1. Mgentry90

    Mgentry90 Member

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    Ca18det was running stage 1 chip and t28 fine. Fitted 444's, z32 afm, Horsham stage 3 chip and a manual boost control valve but now not running properly. Idles fine as I believe it should at around 800-850rpm warm. Went to take it out to set the boost control up to 17psi but it seems to struggle when throttle applied in gear (with load on the engine), also, when you do apply throttle to higher rpm and jump off the throttle the engine rpm will drop right down, dip below idle and will sometimes cut out (cuts out all the time if driving or changing gear doing this, but if it's in the garage stationary and you do the throttle l it will sometimes dip low but recover).

    I've tried another z32 afm, checked the wiring which is:

    A no connection
    B green with black strip
    C black ground linked to D (sure google said to do this)
    D black ground
    E black white stripe
    F no connection
    Green/yellow wire is disconnected on loom

    Two things I'd point out unsure if it's the reason as it was like this running fine before stage 3: I'm running ecu with stage 3 chip, the ecu number is 39F05. The 02 sensor is disconnected but wasn't originally with the engine, I bought the exhaust elbow off eBay with this already fitted and left it in as a home filler. Also, the rocker cover breather T that usually links to the elephant trunk is open to atmosphere as I've run an aluminium intake pipe instead of original trunk hose.

    is anyone who knows what they are doing based near aveley Essex that can pop their nose in and share some advise, or can anyone give some pointers?

    I've checked timing and believe it's correct too at 15btdc, and I've just ordered a selection of vacuum hoses to throw on to replace any old ones. Engine was rebuilt like 500 miles absolute maximum ago.
     
  2. pointz

    pointz Member

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    If you vent to atmosphere you need to blank the pcv (breather off rear of inlet)

    It'll be sucking unmetered air during off boost conditions.



    Block that and see how you go
     
  3. Mgentry90

    Mgentry90 Member

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    Blocked the Pcv but this made no difference. I've just replaced some vac hoses for the sake of a few quid. I've rechecked the TPS and believe this is correct. I've reset idle as when I disconnected the aac valve plug the engine was cutting out, it now idles at 750-800ish.

    anyone got another stage 3 chipped known working ecu I can borrow to test? Was working ok before fitting stage 3 bits
     
  4. Disco_spud

    Disco_spud Member

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    I had similar issue with 1jz. Put a longer pipe between the turbo and afm and sorted the issue. Don't know if that'll help you but might be worth a shot.
     
  5. Mgentry90

    Mgentry90 Member

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    Looking into this now, just ordered a 1m long Hose to put in between turbo and afm as due to limited space they were only a few inches apart at best.
     
  6. Tommy59

    Tommy59 Active Member

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    When you lift off the throttle and the body closes, the air stalls then reverses direction back through the intake I believe. I had a similar issue on my R32 where I needed to have a diverting plate installed in the intake so stop the air flowing backwards through the MAF causing it to stall out. As previous comment mentioned, try a longer intake.
     
  7. r3k1355

    r3k1355 Well-Known Member

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    You need some decent distance and ideally abit of a bend in the pipe between the turbo and afm, otherwise the afm readings get screwed up and the car runs like shit.
     
  8. Mgentry90

    Mgentry90 Member

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    Thanks all, so the 1m hose I fitted made (see below photos) made a heap of difference and I could even drive the car. I will look into proper fitment of the intake hose etc and start again with setting up boost.

    96AE0FCB-B78F-4E7B-B3A6-03175073BC37. 8202532F-8391-432B-90BE-C77B249DCE25.
     
  9. Mgentry90

    Mgentry90 Member

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    This is how close the afm was previously btw..

    CAB74EB2-B636-4211-9D3E-33EF96FC14AE.
     
  10. Disco_spud

    Disco_spud Member

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    Yea that's way too close, the meter long might be a bit of over kill but at least your headed in the right direction.
     
  11. Mgentry90

    Mgentry90 Member

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    Yea the 1m was just to gauge of distance WAS the issue here or not. And you were all right.
     
  12. r3k1355

    r3k1355 Well-Known Member

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    Any scope to bin off one of the headlights? Create abit of space back there for the AFM?
     

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