Overboost issue

Discussion in 'Technical' started by ProckyZ89, Sep 28, 2014.

  1. ProckyZ89

    ProckyZ89 Senior Member

    Ok so I finally got a chance to work on the car and re-assemble it.

    Took it for a drive at 6pm yesterday

    Everything was fine, car seemed happy, pulled well.
    Low boost held it's usual 13psi (raising to 13.8 on wot runs)

    High boost is meant to be 23(sneaks to 24 sometimes)
    High boost however, was spiking over 25-boost controller flagged it and bled it off which only bought it back to 26psi-

    I repeated a 3rd gear pull a few times and soon as I saw it flag (flash red) I backed off straight away -

    Nothing was changed on the car except I did pull the entire intake tract apart and clean vigorously and the intercooler.
    I also cut a hard line on the fuel vapor canister but rejoined both ends with silicon vac hose.

    Just looking for potential ideas where to look at this stage

    TWIN TERROR Well-Known Member

    The fact that the low boost is working tends to show a restriction on the vent side of the boost solenoid either physical or pressure related. Your controller knows what it should be doing but the solenoid is not able to vent the extra pressure so look at the solenoid and the vent side. Maybe double check your plumbing. Mine spiked once when I connected the safety solenoids by mistake.
    That's my best guess.
    Last edited: Sep 28, 2014
  3. MagicMike

    MagicMike Moderator Staff Member

    I rekon you might have fixed some boost leaks.
  4. Martin Williams

    Martin Williams Well-Known Member

    I take you have an EBC and its the EBC controller where you are getting the overboost alarms from?
    Do you have blow off valves or are you still relying on the standard recirc valves?
    Check you have piped up EBC correctly
    Check EBC solenoids are operating correctly, clean out air passages and ensure vents in EBC are clear. They do get some oil in them and after a period of non use can partially stick. The higher boost you run the more oil/water you will get in the system from compression of air.
    Check wastegate actuators are operating properly by introducing an air supply to hoses and measuring actuator arm movements.
    Check all hoses air lines to EBC and wastegates for security and damage.

    Hope this helps
    Last edited: Sep 30, 2014
  5. ProckyZ89

    ProckyZ89 Senior Member

    Yes you are correct
    The EBC was not touched neither were the lines apart from removing to clean pipes.

    Low boost again works perfectly- high boost seems to spike and overrun to 27/28psi

    I havnt checked the actuators or solenoid yet, I turned the controller down from 80% set (mathematically 24psi area) which is where it was tuned for on dyno .

    down to 70% and now I get 24/25psi

  6. Bob Lloyd-Jones

    Bob Lloyd-Jones Oldreverbob

    Some EBC program setups have a adjustable extra boost psi setting with a timer to control the length of time for extra boost,:br: check to make shore this setting has not been activated in the EBC program.:zlove:

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