Fuel Injecting an MGB
These web pages describe two ways of converting the SU/Stromberg carburetor on an MGB to Fuel Injection. Both use a Ford throttle body that contains a low impedance fuel injector and an adjustable fuel pressure regulator. Almost any throttle body of reasonable size will work, the correct fuel injector size is critical. The throttle body schematic shown below is from a Ford mid 1980's Tempo or Taurus
There are three important considerations when converting a car like the MGB to Electronic Fuel Injection (EFI)
- Fuel delivery from the tank to the throttle body
- Throttle body and injector choice
- Computer (ECU)
Installation for the early two carburetor cars and the later single carburetor cars differ somewhat. The fuel feed line from the fuel tank requires different treatment for early cars. The use of a single Throttle Body Injection (TBI) or injectors at a distance from the intake valves is dictated by the siamese intake ports. Although possible, multi port injection adds complexity that most ECU's can not handle. The throttle body requires a custom adaptor for the later single carburetor cars, and a Pierce manifold with adaptor for the earlier two carb cars.
Adding fuel injection to my MGB increased the response, provided a more stable idle and gave an average fuel economy of 30 mpg on mountainous highways and as much as 36 mpg on highway driving..
Two alternatives for the ECU are: the 1980's analog Bosch L-Jetronic and the up to date digital Megasquirt engine management system.