Results 1 to 10 of 10

Thread: Long time Sync (longer time to fire).

  1. #1

    Default Long time Sync (longer time to fire).

    I've converted my Corvette from stock E38 ECU to stand-alone Dominator V4.
    Engine is RHS 427ci with 58x reluctor wheel. Battery still on back at trunk & V12.

    It seems the issue that it's not seeing RPM quickly, so I believe the tuning parameters are not the cause?
    Cranking speed between 80-120 RPM. When it sync it will fire.
    The other issue is that it's killing battery & spark plugs (too much fuels) due to long time cranking and multiple trials until it starts.

    Any suggestions to start and check? From what I have read here, 2-3 seconds is what the folks are getting/aiming to fire their beasts up.

  2. #2
    Join Date
    May 2014
    Location
    Bostwick, GA
    Posts
    136

    Default

    Post your Global File, so others can look. Any datalogging done?
    Injector Inspector
    USAF 1960-1964
    Drag racing since 1955

  3. #3

    Default

    Corvettes have a trunk?
    What size cables are you running from the battery to the starter?
    And did you run both positive & negative cables from the battery to the starter?

  4. #4

    Default

    Current tune file has been attached.
    Datalog 1 & 2: Fired up
    Datalog 3 & 4: No startup.
    ---------
    DBC throttle, no IAC installed.
    Last edited by white_shark; 02-21-2018 at 05:43 PM.

  5. #5
    Join Date
    Nov 2014
    Location
    Ont. Canada
    Posts
    938

    Default

    If you look at your datalog, you'll see it's seeing your RPM, but not starting. Look at your IAC, the Park Position is around 32%. That would probably be way too low, not giving it enough air. That's why it fired when you pumped the throttle. Put the IAC Parked Position at 80% and then lower it with testing to see what works. Then once it starts and the idle RPM settles down, the IAC goes to 100%, which would tell me your throttle shafts need to be adjusted.
    Your cranking volts look pretty good. It spikes down to around 10.1V on initial hit, then settles in around 10.9 as it turns over. Your cranking RPM is maybe a little low. It is around 100. I see about 180 on mine. How old is the starter?
    You may also want to look at your Injector End Angle. Yours is at 0 right now. Enable the table and edit it. This is what worked for me: https://forums.holley.com/showthread...d-Angle-Tuning
    Last edited by 81 TransAm; 02-21-2018 at 09:37 PM.

  6. #6

    Default

    If you look at his post, it says no IAC installed. I'm wondering if that's the problem.

  7. #7

    Default

    Quote Originally Posted by HotRodLincoln View Post
    If you look at his post, it says no IAC installed. I'm wondering if that's the problem.
    Yes, I'm running a Wilson DBC throttle body with no IAC provision.

    Quote Originally Posted by BITE_ME View Post
    What size cables are you running from the battery to the starter?
    And did you run both positive & negative cables from the battery to the starter?
    I'm not sure about the size, it's a big one maybe 0.6" diameter. Both positive & negative cables run from the battery in rear up to front on a fixed terminals on firewall. Starter cables also connected to those terminals from firewall.

    Quote Originally Posted by 81 TransAm View Post
    If you look at your datalog, you'll see it's seeing your RPM, but not starting. Look at your IAC, the Park Position is around 32%. That would probably be way too low, not giving it enough air. That's why it fired when you pumped the throttle. Put the IAC Parked Position at 80% and then lower it with testing to see what works. Then once it starts and the idle RPM settles down, the IAC goes to 100%, which would tell me your throttle shafts need to be adjusted.
    Your cranking volts look pretty good. It spikes down to around 10.1V on initial hit, then settles in around 10.9 as it turns over. Your cranking RPM is maybe a little low. It is around 100. I see about 180 on mine. How old is the starter?
    You may also want to look at your Injector End Angle. Yours is at 0 right now. Enable the table and edit it. This is what worked for me: https://forums.holley.com/showthread...d-Angle-Tuning
    Thank you for your information, I will let the tuner look into it. Please note that I have no IAC though.

  8. #8
    Join Date
    Nov 2014
    Location
    Ont. Canada
    Posts
    938

    Default

    Quote Originally Posted by white_shark View Post
    Thank you for your information, I will let the tuner look into it. Please note that I have no IAC though.
    No IAC will make it a little harder to start. You could crack the throttle a little on startup. Hold it open a little. Watch your display to see the TPS % you're at, and then find the % that works the best.

  9. #9
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    19,255

    Default

    NOTE: The engine won't start if the throttle is opened (TPS Position %) beyond the "Clear Flood TPS" setting (in Engine Parameters). I program the "Clear Flood TPS" at 75%.
    May God's grace bless you in the Lord Jesus Christ.

    '78 BRONCO: 508" stroker, TFS heads, 11:1 comp ratio, Dominator MPFI & DIS, cold air induction, Spal dual 12" fans/aluminum radiator, dual 3" exhaust/Magnaflow mufflers, Moroso vacuum pump, Accusump, engine oil & trans fluid coolers, 100HP progressive dry direct-port NOS, A/C, LenTech Strip Terminator wide-ratio AOD/2500 RPM converter, 3:1 Atlas II, modified Dana 44/60-lockers-4.10s, hydroboost/4-disc brakes, ram-assist/heim joint steering, Cage long radius arms, traction bars, 4" Skyjacker lift, 35" mud tires

  10. #10

    Default

    I’m running a Wilson DBC throttle body also, but with an IAC provision. If you didn’t get one IAC capable, you can always do a remote IAC.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us