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Thread: Runs great, then dies for no apparent reason?

  1. #1


    I have an Atomic/6A on a BBC 502 480 HP internals/specs unknown in a 86 K30 manual transmission, running PWM no regulator for the moment, GM HEI distributor no module, locked out, manual fan. Once I got everything hooked up correctly except the not used wires, it fired and ran at a high idle smoother than ever. Then died, started again and adjusted the throttle blades, and it ran perfect around 680-720 RPM then died again. It doesn't seem to want to fire back up. I have adjusted the throttle again and powered down a couple of times with no luck. Thoughts on why it's dying? I went through the diagnostics and it had a WBO2 error?

  2. #2


    Since it doesn't want to start currently, look on the handheld in the Atomic dash section and check to see what the RPM shows. If it doesn't have RPM, it will not fire the injectors or the fuel pump. Also, I know you said it shows the WBO2 sensor error. Does it show anything for the fuel pump while cranking the engine over? Does the handheld shut off while cranking as well? Where is the black wire out of the power module grounded?

  3. #3


    It appears that there's no tach signal from the 6A controller. I'll be upgrading it to a new 6AL or similar and try again.

  4. #4


    Question on your 6A box. Where do you have that box grounded to? Since it's acting intermittently it maybe a poor ground for the box.

  5. #5


    We determined that the 6A was not putting out a tach signal any longer. I replaced the 6A with a 6EFI and everything is going well so far. I'm looking to put a couple of hundred miles on it tomorrow.

  6. #6


    If you run the car for some reason really rich, you have to take out the WBO2 sensor and clean it. Maybe this works for a few days or "forever", but it seems your WBO2 sensor is dead and you have to put in another one. I have the same issue, and came back to work safely after changed the WBO2 sensor.

  7. #7


    I have about 800 miles on the new system now and there is only one issue, it happens daily but for no apparent reason. I turn the engine off and go into the store, return and turn on the ignition and the Atomic gauge reads 135 psi, I have found that it will not start until I adjust the throttle blades. I know when I turn the ignition on and the Atomic controller fuel pressure reads 30-50 psi it will start & run, if it reads 135 psi just get out and adjust the throttle blades because it's not gonna start.

  8. #8
    Join Date
    Oct 2018


    I think you are mixing up here something. 135 psi of fuel pressure and then you tell that you need to adjust the throttle blades? You may mean the IAC Position which could be 135 -> This value will change when adjusting the throttle blades.

    So in other words you mean if IAC = 135 the engine does NOT start as soon as you adjust the throttle blades, so that IAC reads 30-50 and then it fires right up? Or does it fire up and dies instantly again? Or stumbling and then dies?

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