Results 1 to 4 of 4

Thread: Why does my SDOL car run richer in cooler weather?

  1. #1
    Junior Member BHC5's Avatar
    Join Date
    Jun 2017
    Posts
    10

    Default Why does my SDOL car run richer in cooler weather?

    Just curious if it's a setting I'm missing or do I have a bad sensor or what? The issue is: A/F ratio goes rich when the outside temps are below 54 degrees F. But above that point at above 60 degrees F. the A/F ratio is good.

    When I say richer, it goes from cruising in the 13's to cruising in the 12's and light loads=11's, too fat. As soon as the outside temps warm up the A/F ratio goes back to normal. Notice on cool mornings then changes as the day warms up.

    (Note: Tuned for E10 fuel so 13.1 is the happy place for this ride at light cruise)

    I'm a part-time DIY tuner, still learning so please be nice



    Tune file attached
    Attached Files Attached Files

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Do the IAT and MAP pids show correct values...?

    Post a log file.

  3. #3
    Lifetime Member
    Join Date
    Mar 2009
    Posts
    746

    Default

    Mine did the same thing. I nailed the VE years ago and the test drive rewarded me with commanded AFRs matching commanded perfectly. Once winter set in it was pig rich, so I switched to CLSD. Now I run the MAF and it's nice and consistent. I had a standalone back in the day that did the same thing, and my friend using an Apexi Power FC in speed density has just experienced the same phenomenon.
    1998 GMC Sierra K1500 5.7/4L80E, longtubes, 411 w/COS 5, marine cam/intake, Whipple. 91 octane at 6000'.
    1997 GMC Sierra K3500 7.4/4L80E, 411 w/COS 3, Whipple, small cam.
    2004 Corvette Z06 with longtubes.

  4. #4
    Lifetime Member
    Join Date
    Mar 2009
    Posts
    746

    Default

    If you were to upgrade to an LS1B PCM and COS5, there is a table A0014 that is an IAT VE multiplier that's aimed at fixing your exact problem. I'm looking at doing another calc.vet to base this off of and take some good notes when I do so I'm not trying to remember that day in 6 months when I want to tweak it for summer use.
    1998 GMC Sierra K1500 5.7/4L80E, longtubes, 411 w/COS 5, marine cam/intake, Whipple. 91 octane at 6000'.
    1997 GMC Sierra K3500 7.4/4L80E, 411 w/COS 3, Whipple, small cam.
    2004 Corvette Z06 with longtubes.

Similar Threads

  1. Is there any way to run the car in OL just while WOT
    By wesam in forum Gen IV V8 Specific
    Replies: 28
    Last Post: December 26th, 2012, 05:35 PM
  2. how do i tell what's causing my car to run rich?
    By VRCALAIS. in forum General
    Replies: 5
    Last Post: April 21st, 2012, 08:17 PM
  3. car wouldnt run with RR
    By minytrker in forum RoadRunner Real-Time PCM Emulator
    Replies: 12
    Last Post: June 23rd, 2010, 07:20 AM
  4. What should I run my car in....
    By 98SS2836 in forum Gen III V8 Specific
    Replies: 3
    Last Post: April 3rd, 2007, 01:15 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
  •