Page 3 of 3 FirstFirst 123
Results 31 to 35 of 35

Thread: Troubleshoot surging at idle

  1. #31
    Fuel Injected!
    Join Date
    Dec 2017
    Location
    Minneapolis, MN
    Posts
    47
    I have had a few things going on outside of working on my old GMT400. I got back to it a little last night. I found that my timing tab is off by 2 degrees. So when initial timing is set to 0 by the tab, the real timing is actually 2 degrees retarded. So my question is how do I deal with this in the tune?
    I'd like to leave the external parts alone so that the next owner can set up timing as they should with a stock vehicle to 0 degrees initial on the tab.
    The $0D mask doesn't seem to like negative values for initial timing. Do I just add 2 degrees advance to my timing table?
    I basically have the timing table from fast355 yet only changing some in the idle area to keep it from surging (May not have been due to timing)

  2. #32
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    move the dizzy 2 forward and remark plate

  3. #33
    Fuel Injected!
    Join Date
    Dec 2017
    Location
    Minneapolis, MN
    Posts
    47
    If I am remarking the plate, do I still set to 0 or am I better off to put in some additional mechanical advance?
    Since the great majority of the timing table is advanced, it would seem that adding some mechanical advance would be beneficially to stability.

  4. #34
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    most bins are set at zero advance on the dizzy

  5. #35
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    some one on here recommended to zero out the stall saver, I haven't tried that yet I don't have a radical cam but it idles and drives better at low rpm's if the base timming is 0 bin set at 22-26 degrezz at the kpa and rpm it's ideling at

Similar Threads

  1. 5.7 TBI w/4l80 surging on deceleration
    By chris989 in forum GM EFI Systems
    Replies: 0
    Last Post: 11-10-2017, 03:12 AM
  2. Need help solving surging deceleration and idle
    By Chewy1576 in forum GM EFI Systems
    Replies: 25
    Last Post: 02-21-2016, 03:17 AM
  3. surging idle switching from sync to async
    By mike65 in forum GM EFI Systems
    Replies: 9
    Last Post: 05-08-2015, 05:47 AM
  4. 7427 hunting/surging idle
    By 1BadAction in forum GM EFI Systems
    Replies: 23
    Last Post: 01-12-2015, 09:35 PM
  5. Need some help, TBI/Vortec Conversion Troubleshoot
    By maxplusten in forum GM EFI Systems
    Replies: 1
    Last Post: 01-17-2014, 12:07 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
  •