Boost wouldn't go above 8psi with Cobb AP Stage 2

Discussion in 'Modifications & DIY how-to' started by flip, Sep 8, 2006.

  1. flip

    flip Member

    Yesterday and the day before i was driving and noticed that all of the sudden my boost gauge wouldn't go over .05 bars or so... There was a huge power decrease so it wasn't the gauge... The first time I pulled over, turned the car off for a sec, then turned it back on and it seemed to work ok for a bit but then did it again. Then yesterday I reset the ecu with my AP and now it seems fine again. Any idea what might cause this and what the fix is? I was talking with George tonight who mentioned the "pill" in one of the hoses that might need to be changed. I read about this yesterday when trying to find others with the same issue...

    Also when under partial boost and letting off, when the BOV releases, it sounds slightly fluttery. Is that normal?

    Input?
     
  2. crashtke

    crashtke Member Supporting Member

    Pill would not do this all the sudden...could be a vacuum hose came loose though. Almost sounds like you are running at wastegate bost (7-8psi I think).

    Also the AP reset is not a true reset. It just clears any check engine codes. To totally reset, just disconnect the neg terminal on the battery and hit the brake pedal for aboout 10 seconds. Let it sit a few seconds then put it all back. THAT will give you a real ECU reset.
     
  3. flip

    flip Member

    But what would cause this problem that would be fixed by either letting the car sit or turning it off then back on again? After i did the reset with the AP, the problem has not shown up for around 24 hours...
     
  4. moose

    moose Infina Mooooooose!

    You don't want to screw with the pill when you're on a plain stage 2 map.

    Also, when you say BOV are you talking about the stocker or an aftermarket one?

    When you see ~8 psi I would guess that either it's a hardware issue (boost solenoid not working for some reason) or maybe the ECU went into a 'limp home' mode for whatever reason.
     
  5. miloman

    miloman Retired Admin

    i have seen that happen on certain aftermarket BOVs... it isnt bad but setting the spring should help
     
  6. crashtke

    crashtke Member Supporting Member

    Again, check all your vacuum lines going to the wastegate, going to the BOV, going to the boost control.
     
  7. goixiz

    goixiz Active Member

    ^^^^
    check also the connector to the boost solenoid
    Wastegate arm secure ?

    priro to this happen did you play with anything
     
  8. flip

    flip Member

    Haven't played with anything under the hood.

    It is an aftermarket BOV (HKS SSQ). The fluttery thing doesn't really bug me but I thought I'd include it just incase it had some kind of bearing on creating the problem at hand...

    I'm kinda thinking limp mode since it seemed to be fixed after shutting the car off, and even better when resetting the ecu (with AP). What could cause it to do that, and what exactly does the ECU retard when going into limp mode?
     
  9. pEd

    pEd This ain't no Piccadilly!

    flash the ecu back to stock and see if the boost goes back to normal??
     
  10. flip

    flip Member

    Well I don't think that would help seeing as it's working just fine right now. After i reset the ecu with the AP everything seems to be ok. I'm waiting to see if the problem arises agian... I'll keep you guys updated. In the meantime, anyone hear of this problem before?
     
  11. Alex

    Alex Community Founder Staff Member

    Ive heard of the "limp mode" before, however, I am not 100% on the cause of it. I'll see what I can dig up.
     
  12. miloman

    miloman Retired Admin

    i know of limp mode too... but im not sure what boost will drop to if u have AP
     
  13. flip

    flip Member

    I'm beginning to think it wasn't limp mode because everything i read about it says that it would set the rev limit at 3k rpm which was not the case for me...
     
  14. miloman

    miloman Retired Admin

    is that AP's limp mode? sounds more like valet mode
     
  15. flip

    flip Member

    That was for stock. I guess the AP could have a different limp mode... Anyone else know specifics?
     

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