Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: Lc1 wrong readings.

  1. #1
    Junior Member
    Join Date
    Sep 2007
    Posts
    40

    Default Lc1 wrong readings.

    I have a stock 2000 LS1 engine in an impala ss clone. Stock exhaust manifolds cats and dual 2.5” exhaust. I have tried auto ve and maf adjustment couple of time but I have had the feeling that I couldn’t trust the values of my lc1. It has always showed richer then Stoichiometric when in closed loop. (average 14.35 or so). First I used analog output and thought that there was a grounding issue. Then I used serial logging with the same result. When my sensor started to get code 8, I bought a complete new lc1. Now I have tested the new one, and I get the same readings with the new sensor and old controller, and the new sensor and the new controller. The sensor is located on top of the right exhaust tube right where it widens out for the cat, and there is no unusual back pressure. I have tested the exhaust at the tailpipe with a 4 gas analyzer and it shows exact 1.000 lambda.
    How is it possible to get to rich readings from the wideband? What am I doing wrong?

  2. #2
    Lifetime Member mr.prick's Avatar
    Join Date
    Nov 2006
    Posts
    3,195

    Default

    code 8=bad sensor
    A new lc1 may have been overkill.
    The gas analyzer in the tail pipe might show leaner than the lc1 because of the cats.

    It would be interesting to see the lc1 vs. the gas analyzer with the gas analyzer it the opposite side of the lc1 instead of the tailpipe.
    What was the Lambda reading from the lc1?
    Did you calibrate before this test?
    512k RoadRunner Firmware 12.14R
    FlashScan V2 Bootblock V2.07.04 Firmware V2.07.22 EFILive V7.5.7 (Build 191) V8.2.1 (Build 181)
    LC-1 WBO2

    _________________________________________________

  3. #3
    Junior Member
    Join Date
    Sep 2007
    Posts
    40

    Default

    I know that code 8 is sensor related but this problem was there long before the code 8 trouble.
    The gas analyzer show 1.000 in both tailpipes on extended idle but I was not logging the wideband at the same time
    I just mentioned it because it indicates that the narrow band sensors are ok.
    The sensor got a heater calibration and free air just before I logged a test drive.
    Attached Files Attached Files

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

    Default

    It would be interesting to see one or both of your narrowbands logged.

    What is odd is that according to your LTFTS they are very positive..up to +18%..normally you would never get wideband readings that rich.

    Out of curiosity did you rescale your MAF? Your MAF Freq vs g/s look like they are scaled down significantly..which again usually points toward underestimating airflow (less fuel)..your GM DYNCYLAIR are much higher..

    What is your B3601 value?
    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
    Lifetime Member mr.prick's Avatar
    Join Date
    Nov 2006
    Posts
    3,195

    Default

    For some reason serial EQ & Lambda are the same. :confused
    Maybe this is a bug with build 114
    512k RoadRunner Firmware 12.14R
    FlashScan V2 Bootblock V2.07.04 Firmware V2.07.22 EFILive V7.5.7 (Build 191) V8.2.1 (Build 181)
    LC-1 WBO2

    _________________________________________________

  6. #6
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,946

    Default

    Yes, that looks very weird...
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	V2 LC-1 WO2EQR and WO2LAM.png 
Views:	132 
Size:	61.8 KB 
ID:	7818  

  7. #7
    Lifetime Member mr.prick's Avatar
    Join Date
    Nov 2006
    Posts
    3,195

    Default

    tor1965,
    what version of the software are you using?
    Was the BBL or passthru?
    I have a log from earlier today (build 114) and it does not do this.
    512k RoadRunner Firmware 12.14R
    FlashScan V2 Bootblock V2.07.04 Firmware V2.07.22 EFILive V7.5.7 (Build 191) V8.2.1 (Build 181)
    LC-1 WBO2

    _________________________________________________

  8. #8
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,946

    Default

    +1.

  9. #9
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    27,946

    Default

    Builds 115/95 are now available: showthread.php?p=120698#post120698

  10. #10
    Junior Member
    Join Date
    Sep 2007
    Posts
    40

    Default

    Thanks for all the response.
    I have installed the latest software and firmware, and formatted the V2.
    The tune file I am using is a tune that I flashed in last autumn, because I needed earlier shift points when the snow arrived. After I flashed it in I become aware that I had flashed in the wrong file, and not the one I had supposed to use. After the test drive I noticed that it had far less cold knock then my summer tune. The engine knock is annoying the first 10 minute after a cold start, and even worse in the winter. So I just let it stay there for the winter.
    My pcm is a 9354896 that had 344 in stock and I have tried different os auto ve and so one.
    I have newer felt I could trust the result of the tuning, and I feel that the wideband always have tricked me some way.
    My maf is a corvette map modified to something by Pro M. It fits nicely in my air duct but it was a bad choice. I have adjusted the table roughly for it but gave up because of the code 8 Lc1.
    Table B3601 is 14.63
    The software was from mid April. Now everything is updated.
    I used black box logging for the convenience. Here is a new log file from today, and my tune file.
    My plan was to upgrade to an os that is compatible with the cos. I have tried the 156 and 074. It has always bean something strange with the 156 even though I have started from scratch several times. What os should I go for? Should I buy a newer pcm (411) before I spend time on this, any consideration?
    Attached Files Attached Files

Page 1 of 2 12 LastLast

Similar Threads

  1. What are your MAP readings?
    By TFZ_Z06 in forum Gen III V8 Specific
    Replies: 9
    Last Post: April 19th, 2010, 07:48 PM
  2. Torque / HP Readings
    By Duramax 6.6L in forum Duramax 06 LLY / 06+ LBZ & LMM
    Replies: 4
    Last Post: October 9th, 2009, 02:54 AM
  3. Please Help Readings Gone Crazy
    By nm2769 in forum Black Box Logging
    Replies: 10
    Last Post: May 21st, 2008, 04:38 AM
  4. Can you smooth out the AFR readings in FS?
    By Redline Motorsports in forum General
    Replies: 3
    Last Post: October 14th, 2006, 01:27 PM
  5. AFR readings low through EFI
    By Chalky in forum General
    Replies: 2
    Last Post: May 18th, 2006, 02:24 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
  •