Results 1 to 5 of 5

Thread: LBZ MAF Bounce

  1. #1
    Junior Member xploitdiesel's Avatar
    Join Date
    Jun 2012
    Posts
    27

    Default LBZ MAF Bounce

    Had a customer complain of a slight surge at certain times. Sure enough we drove the truck and I logged it and there was a slight surge where desired rail pressure dropped etc... so looking into what could cause this I noticed(wasn't hard to miss) the MAF was bouncing throughout the drive...at idle it was fine and stable, but under load it would bounce to 40 and back to 5 lb/min and the back up...it did this constantly under ANY throttle. The customer has an S&B air intake and I did a quick check for leaks. Is it possible the MAF sensor needs to be cleaned or replaced or is there some quirk I'm missing. This was a DSP5 tune as well running 52606128 OS. The truck ran fine for 6 months, so I was certain it wasn't my tuning that just now caused this...as I have tuned many and this one is a first...
    Regards,
    Kyle Ensley


    X-PLOIT DIESEL PERFORMANCE
    www.xploitdiesel.com
    kyle@xploitdiesel.com

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,752

    Default

    The air intake plumbing/tube/lid/airbox is causing this, install the stock plumbing/tube/lid/airbox and see the MAF bounce minimizes

    ( I see this on gasoline vehicles quite often )

  3. #3
    Lifetime Member tokymon's Avatar
    Join Date
    Apr 2008
    Posts
    227

    Default

    Is it pushing open the egr seen it happen at high drive pressure.
    97 2500 ecsb 5.7l/4l80e/4x4 411 pcm /thorley tri-y's/dual super 40's with x (catless)/aem cai/msd 6a and coil/zz4 cam/beehive spring/lm-1

    stock sucks

  4. #4
    Lifetime Member killerbee's Avatar
    Join Date
    Jan 2006
    Posts
    1,044

    Default

    As stated above, when the EGR opens, the MAF will reduce logically. I don't think 40 to 5 is expected, so I would investigate EGR correlation, before replacing the MAF
    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"

  5. #5
    Junior Member xploitdiesel's Avatar
    Join Date
    Jun 2012
    Posts
    27

    Default

    I should have mentioned that the egr is blocked and disabled.
    Regards,
    Kyle Ensley


    X-PLOIT DIESEL PERFORMANCE
    www.xploitdiesel.com
    kyle@xploitdiesel.com

Similar Threads

  1. 4L80E WOT shifting problem. 1st-2nd bounce rev limiter!
    By TransAm-Z in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 7
    Last Post: August 20th, 2013, 09:41 AM
  2. e38 6.2L conversion from 5.3L timing bounce in park only not drive XXX
    By huttner1 in forum E37, E38 & E67 PFI ECM's
    Replies: 1
    Last Post: June 13th, 2013, 08:31 AM
  3. Getting DTC 0172&0175, WBO2 bounce
    By Ram Air IV in forum General (Petrol, Gas, Ethanol)
    Replies: 1
    Last Post: September 13th, 2009, 06:13 PM
  4. Replies: 10
    Last Post: August 27th, 2009, 09:38 AM
  5. Valve Bounce identification logging
    By oztracktuning in forum General (Petrol, Gas, Ethanol)
    Replies: 0
    Last Post: June 1st, 2007, 12:01 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
  •