Valve float at the drag strip! I think.

Racers Hangout

  1. 2quick

    2quick Well-Known Member

    Messages:
    817
    Likes Received:
    598
    Joined:
    Apr 27, 2010
    Location:
    New Jersey
    Local Time:
    5:50 AM
    Fuel pressure is dead on 46psi and never moves. Running a billet dominator pump..
     
  2. dvw

    dvw Well-Known Member

    Messages:
    4,249
    Likes Received:
    5670
    Joined:
    Feb 16, 2010
    Location:
    waterford mi
    Local Time:
    5:50 AM
     
  3. dvw

    dvw Well-Known Member

    Messages:
    4,249
    Likes Received:
    5670
    Joined:
    Feb 16, 2010
    Location:
    waterford mi
    Local Time:
    5:50 AM
    It doesn't sound like it's on the limiter. It sounds like it's got a cylinder(s) firing at the wrong time. I'd recheck the adjustable rotor. Did it ever act up with the old rotor?
    Doug
     
  4. 2quick

    2quick Well-Known Member

    Messages:
    817
    Likes Received:
    598
    Joined:
    Apr 27, 2010
    Location:
    New Jersey
    Local Time:
    5:50 AM
    I don’t know. Like I said I had the limiter set to 6300 so I never really got into the popping before. I swapped the rotor due to locked out timing and I was having issues with stater kick back. I adjusted the rotor with a hole in another cap and a timing light. Looks like rotor alignment was off so I backed it off and lock it down. Thing is I still get stater kick on occasion.
     
  5. LemonWedge

    LemonWedge Well-Known Member

    Messages:
    431
    Likes Received:
    738
    Joined:
    Dec 27, 2009
    Location:
    Puyallup, WA
    Local Time:
    2:50 AM
    I agree with Ron that the rest of the timeslip seems to be in line with the 11.0’s. Especially soft down low for the combo. This would lead me to think the advance curve may be really out of whack. Is it popping every time it gets to 6300, or only in 3rd gear?
    Take Dwayne’s advice and turn off the limiter. Also, I’m sure that box has a retard function. Are you sure it’s not pulling timing out somewhere in the curve?

    On the positive side: The car looks almost unfairly cool.
     
    Last edited: Sep 30, 2019
  6. 2quick

    2quick Well-Known Member

    Messages:
    817
    Likes Received:
    598
    Joined:
    Apr 27, 2010
    Location:
    New Jersey
    Local Time:
    5:50 AM
    I’m not sure of anything at this point. It does pop anytime I get near the 6500 range but I short shift the 1-2 then pops real bad trying to get through the trap. I think the car wants to trap around 6600-6700 although I can’t get it there to be sure.
     
  7. 2quick

    2quick Well-Known Member

    Messages:
    817
    Likes Received:
    598
    Joined:
    Apr 27, 2010
    Location:
    New Jersey
    Local Time:
    5:50 AM
    This my game plan.
    1. Figure out how to remove the MSD Rev limiter all together. I don’t think there is an actual on/off selection for this but maybe setting the the Rev limit number to zero will work.
    2. Check rotor phasing again.
    3. Separate the distributor pickup wiring from the main coil wire it currently runs along side off.
    4. Also separate the pickup wire from where it goes through the fire wall in the same hole as the coil primary wiring.
    5. I may even run a dedicated ground wire to the one wire alternator.

    This is my plan of attack.
     
  8. PRHeads

    PRHeads Well-Known Member

    Messages:
    457
    Likes Received:
    545
    Joined:
    Aug 31, 2018
    Location:
    So. Burlington Vt
    Local Time:
    5:50 AM
    On my digital 6 box, putting the rev limiter dial at “0” turned it off.
     
  9. 2quick

    2quick Well-Known Member

    Messages:
    817
    Likes Received:
    598
    Joined:
    Apr 27, 2010
    Location:
    New Jersey
    Local Time:
    5:50 AM
    This is a programmable 6. There are no dials. Laptop to make changes.
     
    • Agree Agree x 1
    • 2quick

      2quick Well-Known Member

      Messages:
      817
      Likes Received:
      598
      Joined:
      Apr 27, 2010
      Location:
      New Jersey
      Local Time:
      5:50 AM
      Here is the navigator and then a picture of it expanded to max RPM. think if I just put in zero RPM it will turn off?

      A060D7FC-4255-4A5F-8ACA-1224A876796D.jpeg 4E03D4AF-EEA5-4FBD-85FE-EB089811F645.jpeg
       
    • 33 IMP

      33 IMP Well-Known Member

      Messages:
      1,962
      Likes Received:
      2376
      Joined:
      Dec 21, 2017
      Location:
      taxifornia,soon 2b Arizona.
      Local Time:
      2:50 AM
      I think your rotor phase is probably fine, you did it right, but i think the rest of your attack should solve your problem. Crosstalk in a couple places.
      Digital sixes don't like "neat" wiring much.
       
    • 2quick

      2quick Well-Known Member

      Messages:
      817
      Likes Received:
      598
      Joined:
      Apr 27, 2010
      Location:
      New Jersey
      Local Time:
      5:50 AM
      So it looks like the lowest I can set the Rev Limiter to is 2700, and I still don’t see a place in the tree to turn it off completely. I may need to call MSD
       
    • 451Mopar

      451Mopar Well-Known Member

      Messages:
      1,627
      Likes Received:
      1023
      Joined:
      Oct 25, 2011
      Location:
      Aurora, CO
      Local Time:
      3:50 AM
      3. Separate the distributor pickup wiring from the main coil wire it currently runs along side off.
      4. Also separate the pickup wire from where it goes through the fire wall in the same hole as the coil primary wiring.

      If you are running a magnetic pickup signal wire along all those other wires, that is most likely the problem.
       
    • PRHeads

      PRHeads Well-Known Member

      Messages:
      457
      Likes Received:
      545
      Joined:
      Aug 31, 2018
      Location:
      So. Burlington Vt
      Local Time:
      5:50 AM
      Prior to buying the digital 6 box I was just running the plain old analog 6a...... the one with no limiter.
      Never a problem, ran it for years.
      Decided I needed something more modern........ bought the digital 6, matching e-coil(to replace an ancient ACCEL super coil).
      I had a couple months of trouble free operation before having issues with the limiter.
      After I started running it with the dials at “0”, I moved some wires around, got the shielded pick-up wire, etc......but never re-activated the limiters to see if the problem was gone or not.
      I ended up selling the digital 6 and e-coil, and bought another old analog 6a before they disappeared.
      Someone gave me another used one which wouldn’t fire off the green/purple trigger wire, but worked with points off the white wire.
      I sent it to MSD and they fixed it for $35.
      Around the same time I was “enjoying” my digital 6 box, my friend was also enjoying his.
      He replaced it with an analog 7al-2....... which has been trouble free for years.

      I’m not really sold on the digital stuff.
      The features are nice....... but they def seem fussier than the old analog boxes.
       
      Last edited: Oct 3, 2019
      • Like Like x 1
      • Thanks! Thanks! x 1
      • 2quick

        2quick Well-Known Member

        Messages:
        817
        Likes Received:
        598
        Joined:
        Apr 27, 2010
        Location:
        New Jersey
        Local Time:
        5:50 AM
        I spoke With MSD tech-support today and they want me to return the box. They say that in order for a problem like that to happen from RFI interference it would happen sporadically at any given rpm range. The fact that it happens only at a specific RPM or within 100 RPM of it in either direction it’s probably a short in the chip inside the box. They also said that it’s not the first time they’ve heard it .
         
      • PRHeads

        PRHeads Well-Known Member

        Messages:
        457
        Likes Received:
        545
        Joined:
        Aug 31, 2018
        Location:
        So. Burlington Vt
        Local Time:
        5:50 AM
        My only reply to that is...... at least in my car, the limiter erroneously coming in at 5k, with the dials set to anything 5k or higher........ could not be duplicated with the msd tester.
        With the tester, the limiter worked perfectly at any rpm you set it at.
        With the motor actually running....... it was 5k........ whether it was set at 6k, 7k, 8k, etc.

        When the problem first showed itself was in the burnout box where the motor wouldn’t rev over 5k.
        I thought someone was fucking with me and had turned my limiter down.
        Got back to the pits...... nope...... still set at 7200.
        You could floor it in neutral..... would only go to 5k.
        Moved the knobs up and down....... 5k.
        I thought I was done for the day....... then thought to just turn it to zero to see what happened.
        No more problem.

        Next day at home, hooked up the msd tester....... rev limiter works perfect....... tried numerous settings...... all worked within 10rpm of the setting.

        I unplugged everything, plugged it all back in, wiggled wires, etc...... couldn’t make it act up.
        I figured...... eh, it’s a fluke.
        Turned the limiter back to 7200.

        Next time at the track....... I make a pass or two, no problems.
        Then it started hitting the limiter at 5k again.
        Put it back to “0”........problem gone.
         
        Last edited: Oct 4, 2019
      • 2quick

        2quick Well-Known Member

        Messages:
        817
        Likes Received:
        598
        Joined:
        Apr 27, 2010
        Location:
        New Jersey
        Local Time:
        5:50 AM
        FYI MSD also said that in order to turn off the Rev limiter completely I need to Set the value to the highest available in the software.
         
      • PRHeads

        PRHeads Well-Known Member

        Messages:
        457
        Likes Received:
        545
        Joined:
        Aug 31, 2018
        Location:
        So. Burlington Vt
        Local Time:
        5:50 AM
        Worth a try.
         
      • 2quick

        2quick Well-Known Member

        Messages:
        817
        Likes Received:
        598
        Joined:
        Apr 27, 2010
        Location:
        New Jersey
        Local Time:
        5:50 AM
        Set the limiter to the limit at 12500 and it pulls straight through 7200 and feels pretty good no popping or flames. I guess that confirms it’s a Rev limit issue. Going to send box back and see if it fixes the issue.
         
        • Like Like x 1
        • Dan64

          Dan64 Well-Known Member

          Messages:
          358
          Likes Received:
          352
          Joined:
          Dec 27, 2018
          Location:
          South Jersey
          Local Time:
          5:50 AM
          What did it run?.
           
        1. This site uses cookies to help personalise 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.