318 wont start and backfires out the carb?

Small Block Mopar Engine

  1. Cope

    Cope Fusing with fire

    Messages:
    3,508
    Likes Received:
    3891
    Joined:
    Oct 20, 2009
    Location:
    San Jose, Ca.
    Local Time:
    6:10 PM
    This is strange, Im trying to hear the roar of open headders (just installed) and my 1971 dart will only pop out the carb?

    I have tripple checked my plug wires and they seem ok. I had the rotor off and the cap sitting on the manifold when I raised the engine for installing the headers so I dont think I dammaged cap or rotor.

    What the heck could have gone wrong?
    What else may I be overlooking?

    Thanks so much for all the help.
     
  2. Lonewolf3165

    Lonewolf3165 Living the Dream!

    Messages:
    1,503
    Likes Received:
    92
    Joined:
    Feb 18, 2011
    Location:
    Collegeville, PA.
    Local Time:
    7:10 PM
    Got to be a timing issue. Did you remove the distributor for any reason? Could it have been moved by accident? You need to check the timing. Sounds like it is way off. If the distributor was removed it's easy to reinstall it 180* off. Was the rotor reinstalled correctly?
     
    • Like Like x 1
    • Cope

      Cope Fusing with fire

      Messages:
      3,508
      Likes Received:
      3891
      Joined:
      Oct 20, 2009
      Location:
      San Jose, Ca.
      Local Time:
      6:10 PM
      The rotor keys into the shaft and can only go on one way.
      I did not remove the distributer just the cap and rotor.

      Ill slap the timing light on and see where im at.

      Im scratchin my head on this.

      Thanks.
       
    • Robj

      Robj FABO Gold Member FABO Gold Member

      Messages:
      1,143
      Likes Received:
      162
      Joined:
      Jan 1, 2012
      Location:
      Redding, California
      Local Time:
      4:10 PM
      You had the wires off the cap it sounds like? I'd check it again. Set the engine at TDC and see which plug wire on the cap the rotor is pointing at. They might be in the right order but a spot or two off.
       
    • 67Dart273

      67Dart273 Well-Known Member

      Messages:
      39,793
      Likes Received:
      7408
      Joined:
      Oct 14, 2010
      Location:
      Idaho
      Local Time:
      4:10 PM
      Yup. Look at "what you did" at the time you last ran it.
       
    • pishta

      pishta I know I'm right....

      Messages:
      14,890
      Likes Received:
      4532
      Joined:
      Oct 13, 2004
      Location:
      Tustin, CA
      Local Time:
      4:10 PM
      Your cap all the way on? It can be cocked and still almost run. Backfire is easy, its fire in an open intake valved chamber. Remember the rotation is CW 18436572 driver side from front 1357, pass 2468. Rotor should point toward front driver side intake bolt at #1 TDC and
      Ike wire so as to let the vacuum pot point to pass side but that's not critical.
       
    • Cope

      Cope Fusing with fire

      Messages:
      3,508
      Likes Received:
      3891
      Joined:
      Oct 20, 2009
      Location:
      San Jose, Ca.
      Local Time:
      6:10 PM
      HA HA!!

      You are THE MAN Lonewolf!!!

      I had the dang rotor not keyed into the shaft..
      rookie mistake..

      Thanks again guys!!!
       
    • Robj

      Robj FABO Gold Member FABO Gold Member

      Messages:
      1,143
      Likes Received:
      162
      Joined:
      Jan 1, 2012
      Location:
      Redding, California
      Local Time:
      4:10 PM
      So.....how do those open headers sound???!!!
       
    • Lonewolf3165

      Lonewolf3165 Living the Dream!

      Messages:
      1,503
      Likes Received:
      92
      Joined:
      Feb 18, 2011
      Location:
      Collegeville, PA.
      Local Time:
      7:10 PM
      It happens. Don't ask me how I know these things!

      Glad I could help you out! No go make some noise!!:burnout:
       
    • Cope

      Cope Fusing with fire

      Messages:
      3,508
      Likes Received:
      3891
      Joined:
      Oct 20, 2009
      Location:
      San Jose, Ca.
      Local Time:
      6:10 PM
      Well Fu#k..

      FRICKIN thing fired right up(Sounds great!!!!) , ran some smoke off the the hedders and shut her down.
      Went to restart and just cranks and cranks.

      Put timing light on No1 and no light, Put light on No8 ,No light.. Put light on coil wire and some light. (3flashes stop 3 flashes stop.) so coil and MSD apear to be working.

      I guess im gonna get a new cap and rotor in the AM, maybe have my coil checked and hope I can get this dam car to run/move.. Plug wires are new as are plugs..

      Gonna drink on this one...

      Thanks for any ideas or advice.
       
    • krazykuda

      krazykuda Well-Known Member FABO Gold Member How-To Section Editor

      Messages:
      48,179
      Likes Received:
      13190
      Joined:
      Aug 20, 2007
      Location:
      Orland Park, IL
      Local Time:
      6:10 PM
      have you set the reluctor gap in the distributor? .007"....
       
    • AJ/FormS

      AJ/FormS 68 B'cuda fb, Form S clone ... 367/A833/3.55s FABO Gold Member

      Messages:
      16,274
      Likes Received:
      5049
      Joined:
      Jan 19, 2014
      Location:
      South-Central Manitoba,Canada, 900ftelevation
      Local Time:
      6:10 PM
      Umm.Recheck the rotor? Maybe the shaft tore the lug partly out of the rotor on the first go-round, then finished the job at 2nd run.
       
    • bruceo2011

      bruceo2011 Still waiting for Y2K

      Messages:
      874
      Likes Received:
      158
      Joined:
      Jan 8, 2011
      Location:
      One of the 10,000 lakes in Minnesota
      Local Time:
      6:10 PM
      ^^^^^^^ Yep. Rotor just might be freewheeling on the shaft.
       
    • 74swingerlover

      74swingerlover Well-Known Member

      Messages:
      203
      Likes Received:
      2
      Joined:
      Feb 19, 2009
      Local Time:
      6:10 PM
      If you are running a Holley, check your power valve after a backfire
       
    • toolmanmike

      toolmanmike FABO Staff Staff Member FABO Gold Member

      Messages:
      40,109
      Likes Received:
      22935
      Joined:
      Jan 18, 2006
      Location:
      Iowa
      Local Time:
      6:10 PM
      Friggen' MSD's
       
    • RedFish

      RedFish Well-Known Member

      Messages:
      23,420
      Likes Received:
      2240
      Joined:
      Sep 5, 2007
      Local Time:
      6:10 PM
      If the rotor was turning ( did cause backfire ) while not properly seated on the shaft, this likely damaged rotor and cap. If one of the contacts in the cap turned 90 degrees, that could break the locator tang out of the rotor.
       
    • Cope

      Cope Fusing with fire

      Messages:
      3,508
      Likes Received:
      3891
      Joined:
      Oct 20, 2009
      Location:
      San Jose, Ca.
      Local Time:
      6:10 PM
      Could you explain this process to me? Unsure what this is or how to do it?


      Toolmanmike.
      Any way to check my MSD box with out sending in?

      Heading out to get a new cap and rotor now, well see if that solves my issue..

      Thanks again.
       
    • Cope

      Cope Fusing with fire

      Messages:
      3,508
      Likes Received:
      3891
      Joined:
      Oct 20, 2009
      Location:
      San Jose, Ca.
      Local Time:
      6:10 PM
      Got it. The metal pickup on top of the rotor was bent down from the rotor not being set all the way down on the shaft.
      A new rotor and she fired right up!!

      Thanks guys!
       
    • Bad Sport

      Bad Sport HALF A BUBBLE OFF Staff Member FABO Gold Member

      Messages:
      35,856
      Likes Received:
      15344
      Joined:
      Jun 12, 2010
      Location:
      The Wolverine
      Local Time:
      7:10 PM
      How would that affect no spark? :scratch:
       
    • Lonewolf3165

      Lonewolf3165 Living the Dream!

      Messages:
      1,503
      Likes Received:
      92
      Joined:
      Feb 18, 2011
      Location:
      Collegeville, PA.
      Local Time:
      7:10 PM
      It won't. I think he was just commenting that the Holley power valves are known to blow out after backfires through the carb. Just some preventative advice I'm thinking.
       
    1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
      By continuing to use this site, you are consenting to our use of cookies.