Boost spike/creep?

Discussion in 'ENGINE MANAGEMENT' started by Badmoon, Nov 9, 2017.

  1. Badmoon

    Badmoon Fresh Recruit

    Hi guys!

    Hope I'm doing this in the right topic...

    So my problem is the following:

    I have a 4efte engine with stock ecu and ct9, I have conic air filter, I have toyosports fmic and decat, full stainless steel exhaust system made by a friend, blitz bov, hks adjustable actuator and hks pfc f-con. I've set the actuator to 0.8 bar and from now and then I'm hitting fuel cut. The boost gauge shows a maximum of 1.1 bar. This happens mostly when shifting from 4th to 5th speed (I have the C160 6 speed gearbox) and hit full throttle or on 5th or 6th speed under full load. I also noticed as it gets colder is easier for this to happen.

    I would like to know your opinion on what I should do to prevent this as I don't like it at all.

    Thanks in advance!
  2. 5e colin

    5e colin Registered User +

    port out wastegate penny hole it couses boost creep

    start by turning the actuator down to 6 full revolutions back and try again
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  3. gorganl2000

    gorganl2000 Registered User +

    as 5e colin said, easiest way is to adjust the hks waste-gate and reduce the boost level till it stop hitting fuel cut in those situations.
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  4. Rev

    Rev Registered User +

    Are you using the 20psi hks pfc f-con map sensor or the stock 16.7psi @ 4.9volts map sensor ( usual clip voltage is 4.9volts ) ?
  5. Badmoon

    Badmoon Fresh Recruit

    My mechanic is a bit skeptical about this procedure but I believe more in you guys as you are the ones who know mostly everything there is to know about this engine.
  6. Badmoon

    Badmoon Fresh Recruit

    I've now set the pressure to 0,7 bar but still creeps to 1 bar... Until now no fuel cut but less power... :(
  7. Badmoon

    Badmoon Fresh Recruit

    Thanks for bringing that up. I remember at the time I installed the hks pfc f-con I had to use both for the engine to work properly... maybe I did something wrong? Would appreciate your info on this. I'm using both at the moment.
  8. 5e colin

    5e colin Registered User +

    ya if i was you adjust the actuator more softy ( fc is bad for engine ) unscrew the arm til it just slots over the wastegate arm pin or hole ( depends on turbo a or b )

    our stock turbos wastegate hole is sooo tiny thats where the problem lys coz of your free flowing exhaust

    you will not have this if you run oem exhaust as the back box/muffler blocks the creep as its not free flowing

    port the hole leave 2mm overlap for penny to sit on it will better the creep , also test your hks actuator it might have a smal leak to causing creep
    dunk it under water and fit hose to hks and blow in it any bubbles and its dodgy and needs replacing
    Badmoon likes this.
  9. 5e colin

    5e colin Registered User +

    the stock map has to stay in place when the pfc unit has the E304 rom inside !!!!
    Badmoon likes this.
  10. Badmoon

    Badmoon Fresh Recruit

    What do you mean to adjust the actuator more softly? I've adjusted it yesterday to 0,7 bar and now creeps to 1 bar which has not triggered fuel cut yet.
    My hks actuator is brand new, just bought it one month ago...
  11. Badmoon

    Badmoon Fresh Recruit

    Yes that's the rom I have inside the unit. Still don't know why they send the unit with that 3bar map sensor if the stock one remain as the default setting...
  12. Phil

    Phil Super Moderator

    if its an option and you are determined to get the most out of your current setup

    (ie you want your target boost level from as soon as possible until redline)

    id either go for a more restrictive exhaust or try using the stock inlet and air box with upgraded panel filter.

  13. Rev

    Rev Registered User +

    If the stock map is needed would say that is for normal idle which covers temperature correction and such maybe just for closed loop
    and off boost cruising.

    Stock ecu would give fuel cut thats 4.5v on the manual ecu you exceed that so the pfc fcon has eliminated that fuel cut.
    You seem to be getting clipping/cutting at the limit of the stock sensor as said above 16.7psi @ 4.9volts map sensor usual clip voltage for the actual sensor rating of 1.2.

    Therefore wiring is not giving you access to the 20 psi pfc Fcon map sensor for some reason? or Not sensing open loop ? or dead sensor maybe ?

    I should add here - A Fuel Cut Defencer (FCD) is also included in certain PFC F-CON kits to override the factory fuel cutoff. Do you have an FCD connected, it can lift your boost levels if the correct HKS type is in place.
    Last edited: Dec 13, 2017

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