MG Car Repair: Proper voltage at the positive coil terminal, proper voltage, solenoid

Question
Thank you in advance - I have a 1978 MGB with the CEI 45DM coil and distributor. The car wouldn't start after warming up. Finally determined that the voltage at the positive coil terminal was dropping to 9.5 volts when the starter was turning and when the engine was running. I finally determined that the terminal on the solenoid that supplys 12VDC to the coil during starting had no output and the voltage at the coil was coming through the "resistor" connection. I replaced the solenoid and the car starts everytime now with 13VDC at the coil positive terminal at idle. My question, finally, is - when I advance the throttle the voltage at the coil drops to about 10.5 VDC - is that normal or do I still have a related problem?

Answer
Hi Patrick,
Something is still wrong because the solenoid is suppose to supply full voltage in the start position and when the key releases the solenoid the power to the coil is suppose to be routed through the resistor wire to the coil at a reduced voltage since the coil is not a 12v coil. I can't explain the reverse action you are experiencing. You need to take a diagram and start tracing ignition circuits as it seems something is not connected up correctly. Also check the charge rate at the battery.
Howard