Bringing TBI and Multi Port Fuel Injection to a New Level.     EFI Conversions and Tuning! Seattle to Portland! E-mail Tuning Consultant!
Page 3 of 3 FirstFirst 123
Results 31 to 37 of 37

Thread: TPS vs MAP AE 7427 $0E

  1. #31
    Administrator
    Join Date
    May 2011
    Location
    Lakes Region, NH
    Age
    49
    Posts
    3,064
    I usually end up increasing this value. The amount will depend on injector size, plenum size, fuel pressure, and engine responsiveness. Maybe try 14 ms? Back down if the engine is too sluggish.

  2. #32
    Fuel Injected!
    Join Date
    Feb 2013
    Location
    Euless, TX
    Posts
    1,702
    It would be helpful to know what your pulsewidth is during AE now.

    IIRC 12.5 msec is all the time you have between injector pulses in Asynch. 12.5 msec would be 100% duty cycle. I doubt you are coming close to 12.5 msec during AE. MAP and TPS AE added together would have to have a value of 12,000 usec to max that out.

    Screen shot your TPS/MAP AE and multiplier tables and post it up.

  3. #33
    Fuel Injected! CDeeZ's Avatar
    Join Date
    May 2012
    Location
    Jokelahoma
    Posts
    422
    I tried 14 MS in Max Asynch BPW, Makes it sluggish on throttle tip in, and still lean pops when you smack the throttle open.

    Chris, here are the AE paramters, I returned them to stock. Also here is the pulse width in AE from the last time I drove it. This was with the Max Aynch BPW raised from 12 to 14 Msec.
    Attached Images Attached Images

  4. #34
    Fuel Injected! dud's Avatar
    Join Date
    Jan 2016
    Age
    50
    Posts
    27
    Here are my AE settings. This is an $E6 bin and ,I think, a BDJY mask.

    It's been over a year since I set it up this way so I don't remember all of the symptoms that led me to this set-up. I could make the engine happy in warm weather, then when it would get below 40 degrees, AE would be way off. Rich in some places and lean in others. Thank God for WB02.
    The one thing that really helped me was tweaking the coefficients.
    Now the engine runs really well with the exception of a slight lean spot at tip in when it gets down in the 20's, but only until the engine is heat soaked, so I haven't bothered fixing it yet.

    These settings probably won't work for you, but you can get an idea of what I did to get mine running right. It'll light the tires without effort from a stop light in any weather now.

    My engine is a stock rebuilt 93 TBI block with vortec heads and RamJet "395" roller cam. Also a 46mm throttle body, shorty headers and Edelbrock 7116 intake manifold.

    I'm also running a mildly tweaked LT1 timing table from a station wagon, I think.
    Attached Images Attached Images

  5. #35
    Administrator
    Join Date
    May 2011
    Location
    Lakes Region, NH
    Age
    49
    Posts
    3,064
    The $42 TBI big blocks used a carburetor manifold with a heated spacer. The power level was low on these engines but plenum volume is still large and needs to get enough fuel so it doesn't pop. $42 doesn't have as many AE variables as $0D but you can still develop an idea of the way fuel was delivered.
    Attached Images Attached Images

  6. #36
    Fuel Injected!
    Join Date
    Feb 2013
    Location
    Euless, TX
    Posts
    1,702
    Quote Originally Posted by CDeeZ View Post
    I tried 14 MS in Max Asynch BPW, Makes it sluggish on throttle tip in, and still lean pops when you smack the throttle open.

    Chris, here are the AE paramters, I returned them to stock. Also here is the pulse width in AE from the last time I drove it. This was with the Max Aynch BPW raised from 12 to 14 Msec.
    I see a lot of your problem from that screen shot as well as the BPW during AE. Even if you could reach the highest values you are only giving it 3.6msec of injector pulse.

    This is a WAG based off what I ran with the single plane victor jr 2bbl intake as well as the Weiand 177 blower.

    MAP AE
    0 122
    20 1000
    40 2250
    60 3500
    80 5000


    TPS AE
    0 122
    3.1 500
    6.3 1000
    9.4 1500
    12.5 2000
    15.6 2500
    18.8 3000
    21.9 3250
    25 3500
    28.1 3700
    31.3 3900
    34.4 4100
    37.5 4300
    40.6 4500
    43.8 4700
    46.9 4900
    50 5100

  7. #37
    Fuel Injected! CDeeZ's Avatar
    Join Date
    May 2012
    Location
    Jokelahoma
    Posts
    422
    Quote Originally Posted by dud View Post
    Here are my AE settings. This is an $E6 bin and ,I think, a BDJY mask.

    It's been over a year since I set it up this way so I don't remember all of the symptoms that led me to this set-up. I could make the engine happy in warm weather, then when it would get below 40 degrees, AE would be way off. Rich in some places and lean in others. Thank God for WB02.
    The one thing that really helped me was tweaking the coefficients.
    Now the engine runs really well with the exception of a slight lean spot at tip in when it gets down in the 20's, but only until the engine is heat soaked, so I haven't bothered fixing it yet.

    These settings probably won't work for you, but you can get an idea of what I did to get mine running right. It'll light the tires without effort from a stop light in any weather now.

    My engine is a stock rebuilt 93 TBI block with vortec heads and RamJet "395" roller cam. Also a 46mm throttle body, shorty headers and Edelbrock 7116 intake manifold.

    I'm also running a mildly tweaked LT1 timing table from a station wagon, I think.
    Quote Originally Posted by 1project2many View Post
    The $42 TBI big blocks used a carburetor manifold with a heated spacer. The power level was low on these engines but plenum volume is still large and needs to get enough fuel so it doesn't pop. $42 doesn't have as many AE variables as $0D but you can still develop an idea of the way fuel was delivered.
    Thank you both for offering this insight!! I have been busy with other things past few days, going to get back to studying this now.

    Quote Originally Posted by Fast355 View Post
    I see a lot of your problem from that screen shot as well as the BPW during AE. Even if you could reach the highest values you are only giving it 3.6msec of injector pulse.

    This is a WAG based off what I ran with the single plane victor jr 2bbl intake as well as the Weiand 177 blower.

    MAP AE
    0 122
    20 1000
    40 2250
    60 3500
    80 5000


    TPS AE
    0 122
    3.1 500
    6.3 1000
    9.4 1500
    12.5 2000
    15.6 2500
    18.8 3000
    21.9 3250
    25 3500
    28.1 3700
    31.3 3900
    34.4 4100
    37.5 4300
    40.6 4500
    43.8 4700
    46.9 4900
    50 5100
    Chris,

    Please elaborate. I'm trying to understand what you're telling me. Also, are you suggesting those values from your single plane Weiand TBI for my two Delta AE tables on this one I'm working on? Thanks.

Similar Threads

  1. 7427 PCM with
    By sfara002 in forum GM EFI Systems
    Replies: 3
    Last Post: 02-23-2018, 06:58 PM
  2. 7427 ECM
    By C2500 in forum GM EFI Systems
    Replies: 1
    Last Post: 01-04-2018, 09:40 AM
  3. '80 Corvette 350 4 spd M/T, '93 TBI, '94 454 TB, 7427 PCM
    By rdicarlo in forum GM EFI Systems
    Replies: 16
    Last Post: 01-11-2017, 02:53 PM
  4. Pin out for 7427
    By myburb in forum GM EFI Systems
    Replies: 11
    Last Post: 08-05-2015, 09:55 AM
  5. 305 tpi with 7427 pcm Possible?
    By Aholt91ss in forum GM EFI Systems
    Replies: 67
    Last Post: 08-24-2013, 04:12 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
  •