Results 1 to 5 of 5

Thread: VE Baro multiplier $8D

  1. #1
    Fuel Injected!
    Join Date
    May 2011
    Location
    Alamogordo, NM
    Posts
    330

    VE Baro multiplier $8D

    still trying to get this stalling issue back in line. i live in sin city now and my travel to work takes me up 1200ft and back down. this morning the car didnt stall once, ran great. i noticed that my idle was in the 15.xx range when at the beginning of the trip. when i get to work its in the 13-14.xx range, open loop idle. blms this morning where in the 118 range. re-adjusted the tables, reducing in cells with the low blms. so leaving work, 1200ft higher, it stalled after a short trip to the gas station. kept stalling, wouldnt start without some pedal, afrs in the 12.xx range when i could get it to idle. unplugged the battery so the ecm could reset, drove it a 1/4 mile and back to stalling. messed with the MAT counts v MAT since it was 30* warmer this afternoon, no noteable change, returned it to stock. managed to get on the highway, blms now in the 112 range, WTF. i reduced the VE tables alot and it and still low blms. now after the trip back into the valley, get off the highway and it stalled again. turned the key off while at the traffic light, let it reset, started it up and it was idling normally. now the idle was really lean, still idled great, blms in the 130's, WTF again. thought about it and the VE vs Baro mult table came to mind. so, a few questions...

    does the table affect fuel only, or IAC, spark, IAT, etc too?


    im going to assume that the baro only updates upon startup? unless theres a dedicated baro sensor found under the dash, then it updates every so often? i dont have one, but i could install one since im changing altitudes often. opinions?


    tomorrow im going to note the baro reading, KOEO(key on engine off), in the morning and again once i get to work. once i figure out what the baro is at the higher altitude, which direction do i need to adjust the values in the table to lean it out a bit, up or down?

    also looked at the table conversion and theres only X. does that seem right?

    thanks fellas!

  2. #2
    Super Moderator
    Join Date
    Mar 2011
    Location
    Camden, MI
    Age
    35
    Posts
    3,026
    the barometric "sensor" is the MAP sensor on startup and when going WOT under a specific RPM.

    the baro value effects a lot of things, IAC and VE are the biggest ones. the specific table you refer to is VE compensation only.
    1995 Chevrolet Monte Carlo LS 3100 + 4T60E


  3. #3
    Fuel Injected!
    Join Date
    May 2011
    Location
    Alamogordo, NM
    Posts
    330
    yes, i know the MAP is the baro as well. in 8D the pseudo baro reading qualifiers are 37% of TPS and less the 3600 rpm. since the VE of my engine is drastically different from stock and probably much different than the 350 and 305, the VE mult v baro table is most likely much different than the calculations used in the EEC DA1 strategy.


    heres where i found my answer.....


    http://www.thirdgen.org/techboard/di...ons-730-a.html

    also going to disable the pseudo baro read too....

    Thanks!

  4. #4
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Where you made your mistake was changing VE after you changed altitude. If you left it alone then during startup it would have got another Baro reading and been fine.

    If you get your VE correct then the baro readings will adjust for that VE, just because your VE is so differant then another engine all the Baro reading does is adjust the entire VE for that altitude. Just about everything in fueling is an adjustment off VE. Shouldn't mess with anything until VE is correct, then you normally don't have to mess with anything.

    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
    May 2011
    Location
    Alamogordo, NM
    Posts
    330
    Quote Originally Posted by EagleMark View Post
    Where you made your mistake was changing VE after you changed altitude. If you left it alone then during startup it would have got another Baro reading and been fine.

    If you get your VE correct then the baro readings will adjust for that VE, just because your VE is so differant then another engine all the Baro reading does is adjust the entire VE for that altitude. Just about everything in fueling is an adjustment off VE. Shouldn't mess with anything until VE is correct, then you normally don't have to mess with anything.
    youre right, and it was......until the IAT circuit was fixed lol then it was suck

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
  •