Maybe your coolant system needs a little more "burping". I burped mine by using the heater hoses. The highest hoses on it. Worked pretty well.

I also used a thermostat with the little toggle on the disc part; supposed to help dispell air...I think.

Always let the engine coolant warm up to the touch before putting the radiator cap back on and road-testing the vehicle.

Pull the radiator cap and the puke tank cap and blow compressed air through that line in both directions to remove any gunk that might be in there. Also check the puke tank itself for gunk in the bottom...remove it and clean it out if there is any crap in it.

Wonder if it's some silly problem like bad dist cap, wires, etc.?