Page 1 of 3 123 LastLast
Results 1 to 15 of 36

Thread: WOO HOO...got the programmer, not so happy results of ACHT bin findings....

  1. #1
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463

    WOO HOO...got the programmer, not so happy results of ACHT bin findings....

    Got my eprom programmer today and did not think to get an eraser......

    Ripped the ACHT bin I am running and found that the "Initial Advance" is 10 degrees.

    I was kind of hoping that it would be 0 degrees because that would have explained the seemingly large amount of pinging during the 3-4 gear area of acceleration when I had the distributor timing at 10 degrees.

    I backed the timing down to 6 degrees and still have very light pinging in that area and now am not sure why since I now know what the Initial Advance is set to in the eprom.

    hmmmmmmm....

    What to do next?

  2. #2
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Well you have a ACHT chip for a 2.8L engine in a 3.4L engine... so maybe look for a 3.4L bin and see how far off the timing is?

    3.4L came with 16149396 ECM
    http://www.gearhead-efi.com/Fuel-Inj...Information-DF

    Change injector size, change engine displacement and start to tune it.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  3. #3
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463
    Using the $4e.xdf, it appears that the constant I have to tweak is the "BPW constant for EGR off" parameter. I've set the minimum temp for egr to "FF" in the table and have set the EGR failure bit to 0.

    I did find this thread and based on the formula in that thread, as well as another thread I found from a different board:

    BPC=1461.5*(.567/5.796 gm/sec) -- where .567 is the cylinder size of one cylinder in the 3.4l engine and 5.796 grams per second is the flow rate of the 4.3l injectors I am using. The resulting value is based on 13psi fuel pressure I believe.

    My math shows 142.97
    Last edited by damanx; 03-30-2013 at 03:19 AM.

  4. #4
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Well close but I think you calculated cylinder liter based off 8 cylinders? For 6 cylinders I get 0.4186930249/5.669904625 = BPC 143.899



    TBI
    Val = 1461.5 * (VOL/RATE)
    VOL = Vol of 1 Cylinder in liters,
    RATE = Injector flow in gms/sec

    Did you use the calculator I made?

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  5. #5
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463
    I don't have any software currently to run that.

    Currently installing openoffice......

    If I did it correctly, that is showing the new BPC at

    138.1397605227

    In that spread sheet, it appears the engine size is not matching up.
    Last edited by damanx; 03-30-2013 at 04:21 AM.

  6. #6
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    It's Open Office and FREE! Does everything Microsoft Office does... including opens all MS Office files... Oh and it will save in MS Office format... I think MS Office is out of business...

    Wow three times the file size for all the MS encryption not needed...

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  7. #7
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Quote Originally Posted by damanx View Post
    I don't have any software currently to run that.

    Currently installing openoffice......

    If I did it correctly, that is showing the new BPC at

    138.1397605227

    In that spread sheet, it appears the engine size is not matching up.
    Have to have correct Bore and Stroke for it to be accurate, I just entered one for one of the 3.4L engines...

    There is also a Old fuel pressure table and New Fuel Pressure table

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  8. #8
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463
    Hmmmmm....don't know why but I've always thought the 3.4l was a 207ci.....

  9. #9
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Find true bore and stroke, only change white cells.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  10. #10
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463
    The bore and stroke in that spreadsheet is correct.

    I also don't have old fuel pressure value either.

    Will start with the value of 138 and go from there.

  11. #11
    Fuel Injected!
    Join Date
    Feb 2013
    Location
    Euless, TX
    Posts
    2,308
    The detonation is from the lack of EGR.

  12. #12
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463
    Quote Originally Posted by Fast355 View Post
    The detonation is from the lack of EGR.
    hmmmm......Ugh...I don't want to have to use the stock intake and egr system....

  13. #13
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Quote Originally Posted by damanx View Post
    Hmmmmm....don't know why but I've always thought the 3.4l was a 207ci.....
    1993 Firebird 3.4L engine Bore 3.62, Stroke 3.31 = 204.4 Cubic inches and 3.34L

    Quote Originally Posted by damanx View Post
    The bore and stroke in that spreadsheet is correct.

    I also don't have old fuel pressure value either.

    Will start with the value of 138 and go from there.
    There's nothing in the BPC calculation that needs fuel pressure. The first Value of Val = 1461.5 is AFR of 14.61. If your using E fuel it should be Val = 1413.5 or whatever your fuel E content tests to.

    You could start with 138 or any number, but 143.9 is correct.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  14. #14
    Fuel Injected!
    Join Date
    Feb 2013
    Posts
    463
    Now I am confused.

    My first calculation that included the flow of the injectors gave me a value of 142.

    Using your table, I got 138.

  15. #15
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Me too

    I did find a mistake in calculation of cylinder liters in the spreadsheet because of 6 cylinder, it was originally made for V8 only. But it did not effect BPC because it uses engine liters divided by cylinders entered.
    Attached Files Attached Files

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

Similar Threads

  1. GQ-4X Programmer from MCUMALL.com Review!
    By EagleMark in forum EFI Parts, Supplies, Software and Reviews!
    Replies: 8
    Last Post: 06-23-2013, 09:41 AM
  2. Happy Stuffed American Day!
    By 1project2many in forum Gear Heads
    Replies: 2
    Last Post: 11-23-2012, 08:14 AM
  3. Not happy with hooker headers
    By JeepsAndGuns in forum Gear Heads
    Replies: 7
    Last Post: 10-09-2012, 12:40 AM
  4. swapped injectors results not what I expected
    By PJG1173 in forum GM EFI Systems
    Replies: 11
    Last Post: 02-23-2012, 12:06 AM
  5. Happy New Year!
    By lightning-jr in forum Gear Heads
    Replies: 1
    Last Post: 01-01-2012, 07:47 AM

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
  •