Popping Exhaust under Acceleration

Discussion in 'Technical' started by GOTTAGO, Dec 6, 2009.


    GOTTAGO New Member

    Did a plenum pull the other week, did the normal delet the shit bits, replace all old fuel, water, vac lines with new, paint and look pretty, new 550cc Injectors and a Mine ECU turned for the 550cc, no air leaks or water leaks, Idle air/fuel is around 12.9 but can't test under load because of duel Exhaust, car runs fine, I run 15psi and know pinging, When you give it full throttle it goes great but it also pops a little out the exhaust:confused:, anyone got a hint or a clue as what it cold be, did not do it with other mines and standed Injectors?????????
    I have adjusted the timing and fuel pressure, but im stumped on this exhaust popping when on the gas hard:confused:

    Any help would be great[TIS]

    GOTTAGO New Member

    Sorry and NO pinging at 15 PSI, my bad
  3. zx299

    zx299 Well-Known Member

    Running too rich......

    If you are running 12.9 @ idle you are going to be drowning your cylinders @ WOT. Mines ECU's are reknowned for dumping heaps of fuel in @ WOT, so combined with the fact that your injector latency is obviously too long and you are flooding your engine.

    If you have the new style 550 Nismos, they flow a lot more than the old style so that could be your problem.
    GOTTAGO likes this.

    GOTTAGO New Member

    I was thinking this, but was not sure, but I'll be playing on sunday with it
    cheers for the help zx299
  5. Chrispy

    Chrispy Pretentious Upstart

    Why can't you test AFR's under load?

    Are you using a tailpipe sniffer thing, or a bosch WBO2 sensor in a bung in your exhaust.

    I don't see what the dual exhaust has to do with it.

    GOTTAGO New Member

    when it sit running we bung up one side and it reads fine soon as we un bung it goes nuts, Iv'e had a feeling it been running rich from the smell when I give it shit and the smoke it leaves, not oil burn, I really need a dyno so I can see whats going on.
    Whos a good Dyno to go and see in brisbane that has 300zx Expertise?

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