1. The Turbo Forums - The discussion board for both hard core and beginner turbocharged vehicle enthusiasts. Covering everything from stock turbocharger cars, seriously fast drag racers, boats, motorcycles, and daily driver modified turbo cars and trucks.
    To start posting in our forums, and comment on articles and blogs please

    IF YOU ARE AN EXISTING MEMBER: You can retrieve your a password for your account here: click here.

Misfire at 5k Rpm

Discussion in 'Advanced Tech Section' started by Scrapiron, Aug 15, 2017.

  1. Scrapiron

    Joined:
    Apr 30, 2016
    E85 carb with vent tube extensions. It has 74 jets in the front and 78's in the back. Part throttle cruise is .91 on afr gauge and wot is .72. I can't get rid of a miss like hitting the rev limiter at 5000rpm. I have a digital 6 box with hvc coil and pro billet distributor. Ngk-7 plugs gapped at.028. Any ideas? Fuel has been eliminated I just bought a magnafuel prostar 625 pump. I double checked rotor phase and I do have the adjustable msd rotor. Timing is 34 deg pulling back to 25 at 10psi boost. Plugs look perfect. Sbc 383 is the engine. I can't find this miss.
     
    Scrapiron, Aug 15, 2017
    #1
    Boost Engineer likes this.

  2. tbird

    Joined:
    Sep 1, 2004
    way rich IMO. .78-.80 WOT is plenty.
    But I might start by only taking it down to 29 deg. and .75 lambda to start
     
    tbird, Aug 16, 2017
    #2

  3. Scrapiron

    Joined:
    Apr 30, 2016
    Thanks. I am trying today to get wot in that rang to see if that helps.
     
    Scrapiron, Aug 16, 2017
    #3

  4. H.P.Ranch

    Joined:
    Sep 2, 2011
    Valve springs? Had New Pac 1218x on LS3 hollow stem intake N/A and would float at 6600.
     
    H.P.Ranch, Aug 16, 2017
    #4

  5. Scrapiron

    Joined:
    Apr 30, 2016
    They are new but doesn't mean they're not an issue. I tested them so I know where to set them up. 130 lbs seat pressure
     
    Scrapiron, Aug 16, 2017
    #5
Loading...
Similar Topics - Misfire Rpm Forum Date
DIP or pause in RPM high stall Advanced Tech Section May 31, 2021
Wastegate on cold/inlet side- What REALLY happens to turbo rpm etc? FAO Tom V Advanced Tech Section Feb 23, 2012
BW Airwerks Says " Ill be way off the map and runnin ner max rpm " Advanced Tech Section Oct 24, 2010
Loading...
bridal-shoal