Page 1 of 3 123 LastLast
Results 1 to 10 of 27

Thread: MAP sensor calibration

  1. #1
    Lifetime Member killerbee's Avatar
    Join Date
    Jan 2006
    Posts
    1,079

    Default MAP sensor calibration

    Has anyone else an opinion on what the problem is here?

    At or near seal level, MAP and Baro should be equal. I have noticed idle (no boost) MAP is around 12.0 psi, instead of the expected 14.x psi. Location error, or calibration issue?

    This has been observed on multiple LMM's.
    Michael, Systems Engineer 04.5 D-max LLY, Phoenix, Arizona Email
    Custom Tuning Services
    DURAMAX/CUMMINS ECM's TCM's for sale, all years, 20% wholesale discount available
    EFILive's first VGT "Software Wastegate Tune"

  2. #2
    R.I.P Shawn, 1956-2011 WeathermanShawn's Avatar
    Join Date
    Jul 2008
    Posts
    1,807

    Default

    Quote Originally Posted by killerbee View Post
    Has anyone else an opinion on what the problem is here?

    At or near seal level, MAP and Baro should be equal. I have noticed idle (no boost) MAP is around 12.0 psi, instead of the expected 14.x psi. Location error, or calibration issue?

    This has been observed on multiple LMM's.
    Thats at Key-On, engine not running yet. At that point (before ignition) BARO and MAP would be equal at sea-level (perfect vacuum). At Idle, you have vacuum, so that correlation would not exist.

    Is that what you are asking?
    2002 Black Camaro Z-28 M6 Hardtop 11.0:1CR 425HP/410TQ SAE (400TQ@3500RPM)
    200cc Heads, 228/232 110+2 Cam, 1 3/4" LT's w/catts, GMMG, Koni Shocks, Hotchkis Springs, 35/21 Sways, 17" ZR1's, 3.90 Gears Roadrunner PCM LM-2 Serial Wideband
    EFILive Closed-Loop MAF/SD Hybrid Tune..


  3. #3
    Lifetime Member killerbee's Avatar
    Join Date
    Jan 2006
    Posts
    1,079

    Default

    I don't see how it is even remotely possible to have 2 psi of vacuum at idle at that location, but I am willing to listen.

    Thanks.
    Michael, Systems Engineer 04.5 D-max LLY, Phoenix, Arizona Email
    Custom Tuning Services
    DURAMAX/CUMMINS ECM's TCM's for sale, all years, 20% wholesale discount available
    EFILive's first VGT "Software Wastegate Tune"

  4. #4
    R.I.P Shawn, 1956-2011 WeathermanShawn's Avatar
    Join Date
    Jul 2008
    Posts
    1,807

    Default

    Quote Originally Posted by killerbee View Post
    I don't see how it is even remotely possible to have 2 psi of vacuum at idle at that location, but I am willing to listen.

    Thanks.
    Maybe I am not understanding your question/premise. BARO and MAP will be equal at Key-on at sea-level. Are you saying there is an issue with the Idle MAP?

    My only point is that MAP and BARO are not equal at Idle..only at Key-on. If the Idle MAP is off..maybe I missed the premise of the question.

    Edit: I am working off the premise of a 1 BAR system. If boosted, there may be some assumption I am missing. The only other condition to consider would be MAP Voltage. 0.0 Voltage does not always equate to 0 kPA ( I hit 0.0 at 14 kPa), but I am not sure what your MAP sensor Voltage maxes out at..

    ..So hopefully we are taking about the same issue here..if not perhaps someone can clarify..
    Last edited by WeathermanShawn; June 22nd, 2010 at 12:47 AM. Reason: Clarification...
    2002 Black Camaro Z-28 M6 Hardtop 11.0:1CR 425HP/410TQ SAE (400TQ@3500RPM)
    200cc Heads, 228/232 110+2 Cam, 1 3/4" LT's w/catts, GMMG, Koni Shocks, Hotchkis Springs, 35/21 Sways, 17" ZR1's, 3.90 Gears Roadrunner PCM LM-2 Serial Wideband
    EFILive Closed-Loop MAF/SD Hybrid Tune..


  5. #5
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    The OP's asking about diesel system... no throttle blade so no vacuum due to throttle.

  6. #6
    R.I.P Shawn, 1956-2011 WeathermanShawn's Avatar
    Join Date
    Jul 2008
    Posts
    1,807

    Default

    Quote Originally Posted by joecar View Post
    The OP's asking about diesel system... no throttle blade so no vacuum due to throttle.
    Yea, I have to give up ever answering another question that relates to diesel. OP, forgive my ignorance..I need to read up on diesel's for about a year..
    2002 Black Camaro Z-28 M6 Hardtop 11.0:1CR 425HP/410TQ SAE (400TQ@3500RPM)
    200cc Heads, 228/232 110+2 Cam, 1 3/4" LT's w/catts, GMMG, Koni Shocks, Hotchkis Springs, 35/21 Sways, 17" ZR1's, 3.90 Gears Roadrunner PCM LM-2 Serial Wideband
    EFILive Closed-Loop MAF/SD Hybrid Tune..


  7. #7
    Lifetime Member killerbee's Avatar
    Join Date
    Jan 2006
    Posts
    1,079

    Default

    Actually, in the LMM there is an intake valve, used mainly for reducing oxygen/increasing EGT during dpf regeneration. But it does not appear to be the issue, as one of the trucks I logged has it removed.
    Michael, Systems Engineer 04.5 D-max LLY, Phoenix, Arizona Email
    Custom Tuning Services
    DURAMAX/CUMMINS ECM's TCM's for sale, all years, 20% wholesale discount available
    EFILive's first VGT "Software Wastegate Tune"

  8. #8
    Lifetime Member killerbee's Avatar
    Join Date
    Jan 2006
    Posts
    1,079

    Default

    Is the MAP sensor only good to 37 psia?

    That 37 psi cap on the log is a PIA. What happened to 3 Bar?

    Thanks for the feedback guys.
    Michael, Systems Engineer 04.5 D-max LLY, Phoenix, Arizona Email
    Custom Tuning Services
    DURAMAX/CUMMINS ECM's TCM's for sale, all years, 20% wholesale discount available
    EFILive's first VGT "Software Wastegate Tune"

  9. #9
    Lifetime Member
    Join Date
    Jan 2008
    Posts
    1,169

    Default

    Quote Originally Posted by killerbee View Post
    Is the MAP sensor only good to 37 psia?

    That 37 psi cap on the log is a PIA. What happened to 3 Bar?

    Thanks for the feedback guys.
    LMM's only read to 37? I'm pretty sure i've seen my LBZ in the 40's.
    '07 TBSS, LS2, T42, 3SS, Black on Black on Black, Pretty much stock at the moment. EFILive will fix that

    '06 LBZ/Allison 6speed, EC, LB, 1LT, Leather
    Current Mods: EFI Live/ PTO High Idle Mod/ Factory Exhaust Brake / BD Full Bore/ TransGo Jr./ TTS Twin Lift Pumps/ MBRP 4" turbo back/ Custom air box mod/ BullyDog Outlook Monitor

    465hp/1008tq---7/25/09---Dyno Day Fast Specialties Tuning by ME

  10. #10
    Lifetime Member
    Join Date
    Feb 2007
    Posts
    517

    Default

    Try using the Boost2_DMA PID. I have done a bunch of logging on my dad's LMM and his Baro matches perfectly with that PID, and it goes up to at least the mid 40s, probably higher.

Page 1 of 3 123 LastLast

Similar Threads

  1. E38 fuel level sensor calibration
    By harascho in forum E37, E38 & E67 PFI ECM's
    Replies: 13
    Last Post: November 29th, 2009, 02:39 PM
  2. AutoVE MAF sensor calibration
    By Ritch in forum Gen III V8 Specific
    Replies: 7
    Last Post: June 21st, 2007, 09:33 AM
  3. New pcv - knock sensor calibration?
    By voda1 in forum Gen III V8 Specific
    Replies: 0
    Last Post: June 1st, 2007, 07:42 AM
  4. Which MAP Sensor?
    By mistermike in forum General (Petrol, Gas, Ethanol)
    Replies: 5
    Last Post: May 13th, 2005, 08:01 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •