Bad BCS?

Discussion in 'Modifications And Maintenance' started by project/driven, Feb 12, 2008.

  1. project/driven
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    project/driven Well-Known Member

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    Here's what I've got going on: I installed my Turbo XS FMIC and everything was seemingly fine after 1 day of driving. Today (1 day later) I appear to have no BCS function, the car holds boost right around 8 or 9 lbs, which I believe is the factory WG spring in a FP 16g. I only had time to visually inspect all bcs lines before work. What I'm wondering is if this is the ecu telling this to happen because of changes in the system, or has my Perrin BCS taken a dump? I have the Turbo xs by pass balve set to recirculate, I doubt this would affect my situation, but someone else probably knows better than me. If my BCS is bad how do I test it? If there's anything else I should check I'm open to suggestions, thanks everyone.
    Car set up: 02 wrx with 16g, 650 cc deatchwerks, catless up/tbe, turbo xs fmic, spt intake, open ecu tune.
    previous to fmic install I had an sti tmic, this is the only thing I changed.
     
  2. Nuke
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    Nuke Well-Known Member

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  3. Bullwinkle
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    Bullwinkle Well-Known Member

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    Did you retune for the FMIC? It is possible for the car to disable the BCS if you get enough knock for the car to go into limp mode.

    Do you have the hardware to pull some logs?

    Plugging in the green connectors under the dash and turning the car power to "on" will put the car into test mode. I believe this test mode will cycle the BCS (you should hear the BCS "click" open and closed).
     
  4. w_o_t_boy
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    w_o_t_boy Well-Known Member

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    I would also guess that the advance multiplier has dropped enough to disable boost control or something has become disconnected. That seems more likely than a relatively new Perrin BCS flaking out. Pull a log and check what your advance multiplier is at.
     
  5. project/driven
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    project/driven Well-Known Member

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    I havent had it tuned yet, I was just out testing for boost leaks. It was making more boost than with the top mount. If the ecu has disabled boost, would a new tune straiten me out? I really do need to buy a cable so I can do my own logging.
     
  6. Bullwinkle
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    Bullwinkle Well-Known Member

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    Yes...
     
  7. project/driven
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    project/driven Well-Known Member

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    I'm guessing that the ecu is effin' with me, cause upon further inspection everything looks to be installed properly. Off to teh dyno with me then. Thanks for your help folks.
     
  8. project/driven
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    project/driven Well-Known Member

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    One more question for the smart guys: If my ecu did sense knock and disable my BCS would it trigger a cel? I have a dyno appt. a week from today and would like to make sure I'm ready to go, and do not waste their time as well as my own plus money.
     
  9. TSTRBOY2004
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    TSTRBOY2004 Well-Known Member

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    me wants a ride... thinking seriously about a 16g this year...
     
  10. project/driven
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    project/driven Well-Known Member

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    ^As soon as I get it running right you're on, it was faster than an e46 m3 at the 17 psi it was running with the top mount(only 220 whp), I can't wait to see how it does now with the fmic and like 20 psi!
     
  11. wall of tvs
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    wall of tvs Well-Known Member

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    No there won't be a CEL from the advance multiplier dropping under 4 or whatever.

    Go have somebody log your car first before doing any sort of stupid kneejerk reaction (ie, paying up the nose for a new tune you might not even need).
     
  12. project/driven
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    project/driven Well-Known Member

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    So who wants to run some logs on my car before next wed.?