#JZ Fueling issue before 3krpm

1jhy35 Mar 12, 2018 at 4:44 PM

  1. 1jhy35

    1jhy35 New Member JZMafia Member

    Likes Received:
    Trophy Points:
    Hi guys,

    Wondering if you can provide any thoughts/input on a weird issue I'm having with my Soarer.

    I bought my friends Single Turbo HY35 setup, which he wasn't having the same issues with so pretty sure its something funky with my car...

    Before it starts coming on boost (<3krpm) it goes from light cruise AFR (14.5), then down to like 16.5/17AFR, before then coming on boost @3k and leveling out.

    Oddly, the fueling loss seems to not occur when the car isn't at operating temperature yet and drives/fuels as it should.
    Once at operating temperature, the flatspot in AFR is causing a real delay to the turbo coming on and anything before 3krpm.

    Tried to make a graph to illustrate this, see attached.

    My engine setup is as follows:

    Holset HY35 with 10cm housing, external 44mm Godspeed wastegate to screamer pipe.

    Uprated 255lph fuel pump + I did the infamous 12v fuel pump mod, thinking that it could be due to the crossover point from sending low voltage to high voltage.



    Was previously using NGK BR7's but tried swapping out to BR8's.

    Still stock ECU with 340cc stock injectors for the time being (yes I know....) however my friend I bought the setup from, was the same and not having issues that I am. :(


Share This Page