Results 1 to 8 of 8

Thread: 2 Bar MAP KOEO = 0kPa

  1. #1
    Tuner in Training
    Join Date
    Oct 2010
    Posts
    30

    2 Bar MAP KOEO = 0kPa

    I just upgraded my 1999 Camaro to the 2 Bar operating system and I installed a GM 2 bar MAP sensor (p/n 12615136) in preperation for a turbo. When I have the key on / engine off the new 2 bar MAP reads 0 kPa but as soon as the engine starts it seems to act normal (approx 45kPa at idle and approx 98kPa at WOT). My 1 bar MAP read exactly 101 kPa with key on / engine off. I spent a few hours searching the forum and most people said to reload my config, delete the VCM scanner.cfg file, etc. I tried it all but I still have the same issue. I haven't started tuning yet but my initial tune, config, and log are all attached below. In the log the car didn't start on the first attempt but the MAP went right to 100kPa when I hit the key.

    Is this something I should worry about or should I just go ahead and start tuning?

    I found 1 post where Russ K said he had the same problem on a 3 bar operating system but he never said if he fixed the issue or left it alone...

    http://www.hptuners.com/forum/showth...&highlight=bar

    For reference, here is the MAP sensor I'm using and my mods:
    Stock 1999 LS1 longblock
    317 truck heads
    02-04 Z06 Cam
    Siemen's 60# injectors
    Stock 1999 Camaro exhaust (no turbo yet)


  2. #2
    Advanced Tuner Atomic's Avatar
    Join Date
    Jun 2008
    Posts
    455
    I have the same problem with my 3 bar...I put my voltmeter to the sensor and it works fine, so I assumed its an error somewhere in hpt.

  3. #3
    Tuner in Training
    Join Date
    Oct 2010
    Posts
    30
    Are you still looking for a solution or did you go ahead and start tuning?

  4. #4
    Senior Tuner 5_Liter_Eater's Avatar
    Join Date
    Nov 2005
    Location
    Houston, TX
    Posts
    3,968
    I've seen this on several gen 3's. For some reason they don't seem to power the MAP if the motor is not running. But if it used to work then it may be a function of the custom OS. You could do a write entire back to stock to see if it reads with KOEO.
    Bill Winters

    Former owner/builder/tuner of the FarmVette
    Out of the LSx tuning game

  5. #5
    Advanced Tuner Atomic's Avatar
    Join Date
    Jun 2008
    Posts
    455
    My map is powered through a 12v ignition source that always has power, then its steped down to 5v for the sensor, so the factory power wire from the pcm is not being used. In my case...

  6. #6
    Senior Tuner
    Join Date
    Nov 2002
    Location
    Central Florida
    Posts
    2,503
    You are looking at the "custom-OS MAP" (whatever its
    proper name is) and not the stock or SAE ones, right?

  7. #7
    Tuner in Training
    Join Date
    Oct 2010
    Posts
    30
    correct. I deleted the 1 bar MAP and added the 2 bar MAP.

  8. #8
    Tuner in Training
    Join Date
    Oct 2010
    Posts
    30
    Just ran a google search (in addition to the forum search) and it appears that my issue is normal and I can go on with life. More of an FYI to anyone else with the same issue...


    see post #5
    http://www.hptuners.com/forum/showthread.php?t=6391

    see post #3
    http://www.hptuners.com/forum/showthread.php?t=27733

    If this is true it should be added to the 2 Bar application procedure as a note to save other people's time.