Results 1 to 2 of 2

Thread: Lq9 Swap bucking under WOT

  1. #1
    Member TorqueMonster007's Avatar
    Join Date
    Aug 2013
    Posts
    83

    Default Lq9 Swap bucking under WOT

    Have a neighbor that does body work. Bought a wrecked 05 2500HD and fixed it. Then had a fella he knows put a Lq9 in it with a BTR truck cam (212/218 @111lsa .553/.553 lift) This said installer had someone tune the truck to basically get it to crank and run. Since my neighbor is a carb guy he asked if I could take a look at it as I have my V2. Attached is the tune I was playing around with. However even before I did anything to it, it will buck like a lean buck as RPM tries to clime about around 4k RPM. It was very slow to apply the power. It almost feels like the fuel pump won't keep up with the commanded fuel. Can somebody take a look at this file and see if anything sticks out that would cause truck to at WOT or harder pedal input acceleration feel like it is holding back and bucking gradually as it tries to gain RPM which is slowly. I did not have time to log any specific PIDs but want to know if anything that sticks out to them right off that could cause this issue. Stock Lq9, BTR cam, manifolds with no cats and CIA. Attached are both files below. The original and the one I have played around with (but have not tried).
    Attached Files Attached Files
    2024 3500HD (SRW) Duramax Denali Reserve
    2021 Ram 4500 Limited (Horse Hauler)
    2016 LML 2500HD Duramax High Country with a little help
    2022 Yukon Denali

  2. #2
    Member TorqueMonster007's Avatar
    Join Date
    Aug 2013
    Posts
    83

    Default

    Possibly a fuel pump issue? He also had been running regular gas and I had him fill up with 93oct to allow fuel trims to relearn with better fuel.
    2024 3500HD (SRW) Duramax Denali Reserve
    2021 Ram 4500 Limited (Horse Hauler)
    2016 LML 2500HD Duramax High Country with a little help
    2022 Yukon Denali

Similar Threads

  1. 5.3 swap going lean during wot/pe
    By Dannn in forum Gen III V8 Specific
    Replies: 2
    Last Post: July 15th, 2014, 10:54 AM
  2. Replies: 46
    Last Post: January 1st, 2014, 01:08 PM
  3. 4L80e swap, won't shift 1>2 WOT
    By LS1FREEK in forum 4speed RWD/FWD Transmission Tuning (incl T42)
    Replies: 16
    Last Post: March 21st, 2013, 11:52 PM
  4. 2000 blazer lq9 swap vin# change
    By nick251984 in forum Petrol / Gas
    Replies: 6
    Last Post: May 2nd, 2011, 03:38 AM
  5. Unknown Bucking???
    By hquick in forum General (Petrol, Gas, Ethanol)
    Replies: 33
    Last Post: January 13th, 2008, 11:41 PM

Posting Permissions

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