Welcome to CPGNation.com! Log in or Sign up to interact with the CPGNation community.

Slight misfire thru rpm range

Discussion in 'FAST Support Forum' started by fishhore, Apr 17, 2018.

  1. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    So plugged vac advance today and drove the car. The popping thru the exhaust is worse now and sounds like it’s breaking up thru the rpm range. Anyone got any ideas? I would think where my timing is I should be able to run no problem. Something else is wrong. I’m getting 14v to the coil with the car started. All my header tubes are around the same temp on my temp gun. I’m out of ideas. Only thing I can think of that I haven’t done yet is to pull my covers and adjust my valves. Popping out the exhaust is an engine miss problem and I can’t find it
     
  2. decline

    decline New Member

    Joined:
    Jan 13, 2016
    People say the same thing on yellow bullet. I guess even with copper gaskets it helps to ground the heads to each other with a 10awg (+/-) wire. Those guys take the engine tuning way more seriously than any other forum I've ever read.

    https://www.yellowbullet.com/forum/showthread.php?t=860658

    This is just one thread of many.
    Seems like grounds are key.
    I've got 2/0 grounds now from bat to block/bat to frame/block to body/frame to body/block to frame Everywhere.
    I have 8awg head to head and from same point down to where bat bolts to block.
    150amp Alternators grounded to block with 4awg and so is starter.
    Fastman told me to do this in another thread. Seems like going ground crazy but I don't want any problems.
    I've got those super low EMI plug wires from firecore and NGK R plugs
    All my ignition wires run on the driver side and my ecu wires in passenger.
    Dual post battery also for ecu +/-
    EMI is the devil
     
  3. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    I shouldn’t have any problems with my can plugged and 34* total timing.
     
  4. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    Well builder even suggests 34* total timing. The popping out the exhaust is much less with the vac advance hooked up. If valves are adjusted to tight I could get popping out the exhaust because exh valves aren’t seating correct? And more timing might mask that problem?
     
  5. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    I have black bushing installed. Dizzy is set up how you suggested I do it. With vac can hooked up the puff or miss out the exhaust is very faint but with it disconnected it’s way worse. That’s why I’m wondering if my valves are too tight. I can’t go any higher total advance because I start pinging around 36*. I don’t think this is a timing issue.
     
    Last edited: Aug 8, 2018
  6. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    The cans are not adjustable on the pro billets
     
  7. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    Moderate to hard Accel and the miss dissaperes. It’s only during cruise that it happens or while bringing up the revs in nuetral.
     
  8. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    And like I said with the vac can hooked up giving me more advance during cruise the miss is much softer and almost gone.
     
  9. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    This whole time you have been trying to get me to go leaner now you want me to go richer?
     
  10. fishhore

    fishhore Member

    Joined:
    Aug 15, 2014
    Well I can say that my car is finally dialed in and a joy to drive. After all these years trying to get a slight miss at cruise and stumble resolved I read back on almost every thread on this forum and noticed something that was said on a lot of threads from a member that used to be on here helping a lot named turbonova. He consistently told ppl with problems to not get hung up on the afr numbers and just give the engine what it wants. So after years of trying to run in the 14’s for afr at cruise I reset my tune and started with 13.7 cruise afr with an idle of 13.3 and holy crap it’s a new car. The exhaust note is quieter and happier sounding, it’s smoother and doesn’t take nearly as much throttle to speed up or pass at speed. I wish I would have tried this 4 years ago when I put in the system. I can finally say I’m happy I have this system 100% now. So if your having drivability issues just remember to not get hung up on a number.
     

Share This Page