Bringing TBI and Multi Port Fuel Injection to a New Level.     EFI Conversions and Tuning! Seattle to Portland! E-mail Tuning Consultant!
Results 1 to 9 of 9

Thread: Logging 10 degrees less timing than my BIN should command $0D

  1. #1
    Fuel Injected! woody80z28's Avatar
    Join Date
    Nov 2011
    Location
    Walton, NY
    Age
    32
    Posts
    138

    Logging 10 degrees less timing than my BIN should command $0D

    Trying to figure out why my truck seems low on power. Noticed my datalog is showing 10 degrees less timing than my BIN should be commanding. I matched up a bunch of samples to RPM and MAP in my tune tables and they're all 10 degrees less in the log.

    I'm thinking it has to do with the code 43 I had that I turned off in the BIN. I checked the sensor ohms and the 5v at the wire and they were all good, so I turned it off. Does the computer still "see" something and retard timing?

    9.7:1 Vortec TBI with LT1 roller cam (built and tuned in '11). Just checked cranking psi and they're all about 180.
    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1)
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D)

  2. #2
    Fuel Injected! CDeeZ's Avatar
    Join Date
    May 2012
    Location
    Jokelahoma
    Posts
    344
    Could it be a table or scalar somewhere pulling 10 degrees for some reason that has possibly been overlooked? With the 411 PCM running the show in my turbo 6.0 T56 towtruck I zeroed out pretty much every single timing modifier. I didn't want several degrees of timing sneaking in and out ESPECIALLY with boost being a factor.

  3. #3
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    63
    Posts
    861
    I remember that one member had to change altitutd timming to stop a simler problem,i think that is what it was.

  4. #4
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    2,424
    a lot of gm calibrations will pull a massive amount of timing when there's a knock sensor error code of any kind present, i'd guess that's whats biting you.. if it's still there after disabling the error code, though, i'm not sure why.

  5. #5
    Fuel Injected! woody80z28's Avatar
    Join Date
    Nov 2011
    Location
    Walton, NY
    Age
    32
    Posts
    138
    When I posted this thread it showed the 10 degrees thread you mentioned. I see that bias was still in there so I just took it out and zeroed the table. But that has been that way since '11, so I'm doubting that's it.

    Does disabling a code via the bin just keep from throwing the light? I would guess it would still do its knock sensor test and "see" the result. And possibly still retard there timing based on the result of the test. I've read that some bad knock sensors do ohm out correctly. That may be my issue. Or I'm thinking maybe the plug. Because the wire and sensor test ok.
    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1)
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D)

  6. #6
    Fuel Injected! woody80z28's Avatar
    Join Date
    Nov 2011
    Location
    Walton, NY
    Age
    32
    Posts
    138
    So I zeroed out the altitude spark bias and turned the code 43 back on. Unplugged the computer connectors for a bit and then took it for a drive. Log started out at actual spark in the BIN until 4 degrees of steady retard came in a minute or so into the log. (The 43 reappeared immediately after starting the truck).

    So I turned off the 43 again and it stayed at actual spark everywhere! Feels much better! The altitude bias seems to have done the trick.

    I did get a few knock counts and a couple degrees of retard on that log when I tried to ping it under heavy load in 5th gear. So it seems the knock sensor is actually working, even if it does want to throw the 43 for some reason.
    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1)
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D)

  7. #7
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    63
    Posts
    861
    it maybe picking up knocks when it first starts from the cold temp spark adder if the file you are running has that scaler in it

  8. #8
    Fuel Injected! brian617's Avatar
    Join Date
    Apr 2013
    Location
    Arkansas
    Age
    39
    Posts
    527
    Knock sensor needs to match PCM/Bin. Make sure your'e using a 94-95 automatic* knock sensor with $0D.
    89 K1500 Scottsdale 5.7L 5spd 3:42

    Build specs: 97 4 bolt main block 350ci, Eagle rotating assembly with flat tops and 4 valve reliefs, Dart 165cc/67cc Iron Eagle heads, Manely SS valves and springs 110lbs seat @1.7, GM Ram Jet cam 196/206 @.50 .431/.451, stock intake and throttle body, heads and intake gasket matched, Delco EP377 fuel pump @ 22 psi, 427 PCM.

  9. #9
    Fuel Injected! woody80z28's Avatar
    Join Date
    Nov 2011
    Location
    Walton, NY
    Age
    32
    Posts
    138
    It does have the cold temp spark adder. But it didn't retard until a minute or so after start. AFAIK, the knock sensor is still the stock one to the truck. I bought it almost 10 years ago and it was still auto then.
    80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
    91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1)
    94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D)

Similar Threads

  1. Did you ever just loose 10 degrees timing? Math?
    By EagleMark in forum GM EFI Systems
    Replies: 75
    Last Post: 05-30-2016, 01:38 PM
  2. 8 degrees retard on stock timing table.
    By Scrufdog in forum GM EFI Systems
    Replies: 44
    Last Post: 08-05-2014, 04:14 PM
  3. chevy 5.7 timing degrees?
    By Tyree in forum GM EFI Systems
    Replies: 4
    Last Post: 07-02-2014, 05:30 PM
  4. LT1 Camaro $EE running 41 degrees of timing at WOT
    By 96lt4c4 in forum GM EFI Systems
    Replies: 22
    Last Post: 10-15-2012, 08:28 AM
  5. Silence Command for CCM on $EE.ADX how to?
    By EagleMark in forum GM EFI Systems
    Replies: 2
    Last Post: 10-25-2011, 09:03 PM

Bookmarks

Posting Permissions

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