what voltage should I have at the coil

when in start position full battery voltage will be applied.In the run position the circuit to the coil is through the ballast resistor and will probably be 7 - 9 volts if things are in good working order.
3 volts will cause hard starts,missing and flooding until warmed up.Check all your connections and clean them with a scotchpad.
my money is on the bulkhead connections.