incurable overboost problem (ITS BACK)

Discussion in 'All Things Technical' started by scoobaru mad, Dec 28, 2008.

  1. scoobaru mad

    scoobaru mad Active Member

    had a problem over the last month or so with the car overboosting. try'd cleaning the standard solonoid, replaced the pipes, try'd a bleed valve screwed RIGHT IN, an the old trick with a T piece hose between the compressor housing an actuator. NOTHING worked, any gear hits the fuel cut (an its not the little pipe to the map sensor)

    so av bought an Apexi ACV-R. guess what... ITS STILL DOIN IT? there must be someone on this earth who knows why my turbo WONT stop boosting?

    i was thinking of slackening the actuator arm spring like it says in the AVC-R instructions?

    ANY, an i mean ANY help on this would be great. i have 300 horse's i cant use! its quite frustrating!! :wink:

    Thanks in advance :D
  2. edmy716

    edmy716 Member

    u have pm :wink:
  3. scoobaru mad

    scoobaru mad Active Member

    Right, i was using this to install the avc-r.

    an i noticed a part about the fuel regulator breather pipe thingy, an the boost duty cycle zoo darr thing? can any one set this up? RARRRGH, i love to hate these cars :wink: :D :lol: :lol:
  4. Turbopercy

    Turbopercy New Member

    you still not sorted it mate what is goin on
  5. edmy716

    edmy716 Member

    ive offered :(
  6. AndrewC

    AndrewC Active Member

    If you switch the AVC-R to OFF what boost does it make?

  7. scoobaru mad

    scoobaru mad Active Member

    it makes the fuel cut. basically. theres no stopping it. an i dont wanna unplug the map sensor an c the turbo head for the moon :lol:

    It just goes right round the boost gauge to 1.1bar ish, give or take i cant really see through the squinting of my eye's in anticipation of head butting the steering wheel. when i set the avc-r to 0.5bar, it boosts up to that, then slowly works it way round till THUMP!.. fuel cut.

    Anthony, youve bin Very helpful mate. an what you said the the pm makes 'sound' advice. what would you reccomend to do with the acuator?

    just so people know. Ive checked, re-checked, triple checked, then checked again the piping. there's no cracks, splits, the AVC-R is plumbed correctly. oh the joys of scoobys :lol: :lol: thanks for the replys fella's keep em coming. WE CAN FIX THIS.. i hope :wink:

    HAVE A HAPPY NEW YEAR TOO!!!! :wink:
  8. scoobaru mad

    scoobaru mad Active Member

    undid the jacket ant, seemed ok through 1st an 2nd... until i hit traffic,

    weird thing is, the avc-r is set at 0.95bar, it showed 0.99 underfull boost (it is minus 1 here to be honest), but the boost gauge on the dash showed 0.56bar at the same time? there is witch craft afoot :lol: :lol: gona give it arest for today

    thanks edmy, appreciate that mate! :wink: have a ahappy new year!!
  9. edmy716

    edmy716 Member

    no probs anytime :wink: .

    just to add if the avcr is on a learning mode it will take a few pulls to settle down to the desired boost, if not the duty will probaly need tweaking down.

  10. scoobaru mad

    scoobaru mad Active Member

    ahh right ok? how do you set the duty cycle. bearing in mind, this avc-r is the super one, as in the earlier edition.

    i can set my desired boost, it can monitor injector pulse rate, and (i think am right by this) it tells me the percentage of boost against the injector pulse rate. however, if ive read the manual above correctly (which i probably havnt :lol: ) i think the above that ive just mentioned is goverened by the acuator strength... which i dare'nt touch... cos i break things :lol:

    this took forever to write. i have the mother of all hangover's!!! [​IMG]
  11. AndrewC

    AndrewC Active Member

    With the AVC-R in setting OFF the car should only make actuator pressure ie 0.5bar.

    If the car is still fuel cutting in this mode then there is something else wrong, either the AVC-R is plumbed in wrong, your WG actuator is faulty or the map sensor signal is incorrect.

    Switch off learning mode, it more trouble than it's worth.

  12. scoobaru mad

    scoobaru mad Active Member


    i have this avc-r above, am not as rich as other's unfortuanatey? i dont think you can turn this off i think?


    this is the one i would of had... but coulndt afford :cry:
  13. adz

    adz Member

    Put a hose (with no Tee) directly from actuator to compressor nipple,

    drive car and if it overboosts there is an actuator problem.
  14. scoobaru mad

    scoobaru mad Active Member

    i thought it would do that anyway? as in it would go to 1.2bar ish, an fuel cut is at 14.7 psi, or just over a bar of boost?
  15. adz

    adz Member

    As Andrew pointed out further back -

    linking actuator direct to compressor will only see boost of approx 0.5bar (ie actuator pressure)

    providing the actuator tension hasnt been fecked around with and it is indeed a std actuator ,

    if it still over boosts with only actuator control then check the waste gate opens correctly and if it does try another std actuator (direct to comp)

    Have someone check the Map signal

    if then the turbo operates at around 0.5 bar, you can then go back the boost controller and have it set up by someone who knows what they are doing,

    messing with gain/duty setting can cause boost spikes and can easily be miss interpreted as over boost (peak boost)

    giving the same sudden fuel cut/head in windscreen effect :lol:
  16. scoobaru mad

    scoobaru mad Active Member

    ive linked the compressor to the actuator before now. an it boosted between 0.7 to 0.9bar before it shot to the fuel cut. i still dont know how its possible to adjust boost duty cycle with the avc-r i have. i see your point though. am not messing with it any more. am gonna go an see anthony when i can an get it set up properly.

    i think the Actuator spring strength, needs adjusting to the avc-r. or so it says in the instructions. but setting it i AINT gonna do.

    i believe the next Rolling road day is in march. i wanna get it running perfect for that. only remaining mods are FMIC, apexi ecu, an a map. am looking for 300/300. thanks for the help chaps. Much appreciated. will come an see you Edmy V.soon mate! :wink:
  17. AndrewC

    AndrewC Active Member

    If you're going to get it remapped then why are you fitting an AVC-R?

  18. scoobaru mad

    scoobaru mad Active Member

    it still doin it, i freed up the turbo jacket touching the actuator, so its better in 1st an 2nd.

    to answer your question Andy... i have no idea. it was going cheap. an i thought it might fix my problem... an it hasnt :lol: :lol: :lol:

    i think ive found the boost duty cycle option.... problem is, i dont know the percentage against the boost ratio eg. 0.9bar to 35% boost duty cycle?

    the more i think about it, the more crossed eye'd i become :lol: :lol:

    what the hell does all this mean? my head hurts :shock:

    IMPORTANT Some piston engines use simultaneous injection system for their fuel injection type. (ex: S13 etc.) Please use the rotary vehicle engine type setting for these vehicles.

    2. Preset Boost Pressure Setting

    This unit includes two settings in its memory for two different boost levels with the self learning function working for each setting. Because this unit completes its self learning mode under normal driving conditions, it requires only some simple steps unlike other systems which require a certain type of driving pattern.

    1. Press the SELECT switch and then press A or B. ( Initial setting is at preset A)
    2. Once the selection has been made, press the UP or DOWN button to set the boost pressure.
    The initial settings are 0.75 kg/cm2 for preset A and 1.00 kg/cm2 for preset B. ( Both presets A and B may be preset from 0.50 kg/cm2 - 2.00 kg/cm2 in 0.05 kg/cm2 increments.)
    ! CAUTION The boost pressure may not be set under tie factory boost setting ( The operational actuator pressure. Raising the boost level to excessive levels may lead to engine damage. our company is not responsible for any damage due to excessive boost levels.)
    3. Letting go of the button at the specified boost level will return the screen to the monitor mode completing the setting.

    IMPORTANT * Pressing the UP/DOWN switch in succession after pressing the SELECT switch allows those commands to remain effective. Thus pressing the button only once will return the unit back to monitor mode.

    3. PresetBoost Duty Setting

    Although this unit uses feedback management and the self learning function to automatically control the boost pressure to the specified setting, the valve driving power duty must stay within a certain limit. Since this limit varies from vehicle to vehicle depending oil engine tuning, it is necessary to set each and every individual vehicle.

    3-1 Actuatot Type

    1. Press the SELECT switch for longer than 3 seconds.
    2. Be sure to check that all of the LED'S other than the SUPER AVC-R logo and the digital bar graph have been turned OFF

    3. Once the LED'S are turned off, this shows that the boost control management is OFF making the boost pressure only rise to the factory setting controlled by the factory actuator operation.
    4. Drive the vehicle with the power OFF. At this point, attempt to drive in the gear with the highest load and check the peak boost level.
    5. Normal actuators may range from ~ 0.4-0.8 kg/cm2. The higher the boost level, the lower the duty cycle that is needed to reach the same boost level. As for the actual duty setting, the fundamental rule is if the boost setting is set for 1.00 kg/cm2 and the actuator pressure is 0.4 kg/cm2 the limit is 70% while a 0.8kg/cm2 actuator pressure would denote a 40% limit. Of course if the boost pressure is higher than this the duty limits would be lower and if the boost pressure lower, the duty limit higher.
    6. Using the actual driving data as a base, set the duty setting corresponding to the actual boost pressure.
    7. Press the SELECT switch once again for longer than 3 seconds and turn the power back ON.
    8. Select one of the boost settings A or B.
    9. Press the MODE button for longer than 3 seconds.
    10. If the set boost level is A, then the initial setting will flash 30% (B will flash 50%)

    11. Press the UP/DOWN switch to adjust the duty setting to the necessary levels. ( the duty level settings for A/B range from 20%~90% in 2% increments.)
    12. Press the MODE switch again to set the duty setting.
    13. At this point drive the vehicle again to check the boost level. While in third gear or above if the boost level stabilizes at a point near the specified boost setting the-unit will commence the self learning process to complete the setting.
    14. If the boost level does not rise enough or overshoots ( by over 0.2 k) during step 12 or if the self learning does not start, please reset the duty settings to prevent miscalculations.( return to step 9)

    !CAUTION If the boost level does not rise to the specified level even after the duty has been set to 90%, a problem with the turbo may exist. In these cases, please lower the preset boost level.
    IMPORTANT * Normally, the set duty level is meant to aid the self learning function according to the corresponding boost level but in vehicles which lose boost at higher RPM's, the duty level may be set to a higher level ( A setting which would normally produce a boost overshooting characteristic) to compensate for the boost drop. As the self learning function progresses, the overshoot will gradually be suppressed. ( Please set vehicles which lose boost due to lack of injector capacity by the normal method.)

    3-2 Wastegate Type

    IMPORTANT * Wastegate type vehicles do not differ in the duty setting front actuator type vehicles but the amount of boost control which is possible depends upon the type or spring rate used by the wastegate. As far as the duty setting is concerned, please choose a spring rate which allows the maximum boost pressure to be controlled by a 70% duty setting.

    1. Set the desired boost pressure front preset A or B
    2. Set the maximum set boost level at a 70% duty level.
    3. Drive the vehicle and check the boost level. Adjust the wastegate spring or replace the wastegate spring so that the boost level reaches near the specified setting. While in third gear or above if the boost level stabilizes at a point near the specified boost setting the unit will commence the self learning process to complete the setting.
    4. As for the other preset, please set the preset to the same if not a higher boost pressure setting than the one above. Please change the duty level for the new boost pressure as well.

    !CAUTION ( Same for actuator and wastegate type) Although this unit has a RPM separate self learning function, vehicles maximizing their injectors by 6200 rpm will not be able to use the self learning function during that period because the unit uses the injector signal to read the engine RPM for the self learning function. In order to have more precise boost control, the solution to this problem is to upgrade to higher capacity injectors.*

    * Our company can provide the proper upgrade injectors.
    BCNR33/BNR32/RNN14 550cc/min: Y20000/pc (Part number:404-NOO I)
    ECR3 3/S 14/#PS 13 440cc/min:Y24000/pc (Part number:404-N002)
    IMPORTANT ( Same for actuator and wastegate type)
    * Changes in either the preset boost pressure or duty level will reset the self learning function.
    (Even if the boost pressure was changed and then returned to its previous setting)
    * As long as the basic requirements are fulfilled, the self learning function will automatically proceed under normal driving conditions. Please follow the steps below to speed up the self learning function process.

    1. Drive the vehicle in as high of a gear as possible in order to get the boost pressure to match the specified boost level at the lowest possible RPM. ( the intercept RPM) ( Running the vehicle from the intercept RPM + 1000 RPM is acceptable.)
    2. Next, run the vehicle in the mid and high RPM of a mid-range gear to match the specified boost level.
    3. Repeating steps I and 2 will speed up the self learning function.
    4. If the boost pressure does not rise properly, please reset the self learning function or check the set boost pressure again.

    * Be sure to reset the duty level and repeat the programming sequence from the beginning when modifying either the actuator or wastegate.
  19. scoobaru mad

    scoobaru mad Active Member

    :evil: :evil: :evil: RAGGGHHHH!!!!!! from 9am this morn till 3pm an half a tank of juice :evil:

    i figured out how to turn the avc-r off, an it crept right round to the fuel cut. so to double check, i put a link between the actuator an compressor housing, it crept to the fuel cut. IVE CHANGED THE ACTUATOR.... FUEL CUT! its still doin the same thing. its boosts up to where it programed, holds for a whole second. then somthing gives way, an it rockets to the fuel cut. what the hell is wrong with it???? ive heard alot about turbo's NOT boosting enough? but phyically tryna restrain this bastid to STOP boosting is becoming tiresome! it will not for the love of god stop boosting??? :lol: :lol: :lol:

    This is the perfect excuse for the missus to get rid an part ex for something else, an i have to agree. why have an impreza that cant be driven LIKE an impreza... so from the rest of the other idea's an things suggested? what else could it be chaps? :cry:
  20. scoobaru mad

    scoobaru mad Active Member

    if i opened the waste gate actuator arm up, so the waste gate opened more? also, take a T hose, one off the inlet manifold, an 1 off the compressor housing to allow more pressure to get to the dam actuator, to open the dam thing... would that stop it overboosting?.. bin reading this? tis quite intresting ... l%26sa%3DG

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