had 2 metering units on it both the same problem, its got a slight misfire on cylinder 2, and the boost gauge has a slight flicker which looks like a vacume leak, and i know the fuel pressure regulator run off vacume pressure, but not sure why it only cylinder 2 which makes it misfire, i was thinking either the luggs on the cam are worn or a sticky valve, ive ajusted the fuel to 6 1/4 turns on the black box on side of metering unit, 1 of the blokes i worked with built the engine so im only trusting him on the mechanical side of it, any ideas would be very greatful as it getting to me