QuestionPlease could you confirm what type of fuel pump would be on my 1978 MGB.
I have replaced the points electronic ignition as it was misfiring. I have replaced plugs, HT leads, inline fuel filter, changed the oil and ensure that I always add lead replacement additive when putting fuel in the car. The first day after replacing the points, the car ran very smoothly but now it misfires initially under acceleration. Please could you give suggestions of what it might be %26 if car has mechanical pump, if beneficial to change. Many thank, Grant
AnswerHi Grant. Your MGB should have a rear-mounted SU electric fuel pump, with the lid accessible behind a black metal cover that you will find in the boot, on the right behind the spare wheel. It should be an AUF300.
When you turn the ignition on, listen before you start the engine.
You should hear a brrrt...tick...tick sound that stops when the fuel pump has pressurized the fuel line.
If it sounds like chug-a,chug-a,chug-a then maybe the points in the pump need a clean or replacement.
But your symptoms do not sound like a problem with the fuel pump.
I do have some suggestions:
1) Have you checked that the SU Carbs have oil in the dampers?
2) Are you sure that your new electronic ignition is correctly timed?
3) Check the wires to the coil. The power lead should go to the + terminal.
4) When you fitted electronic ignition, did you run a new power supply to the coil, bypassing the ballast resistor inside the wiring loom? If not, your system is only running on 8 volts.
