Method and apparatus for synchronous switching of fuel injection control signals

An assembly for use with an engine system that includes a first plurality of fuel injectors configured to deliver liquid fuel to corresponding cylinders of the engine wherein the engine is further configured to operate on compressed natural gas (CNG) fuel, comprising:

• a second plurality of fuel injectors configured to deliver CNG fuel to corresponding cylinders of the engine;
• an injector selector configured for connection to the first plurality of fuel injectors and the second plurality of fuel injectors, said injector selector being configured to switch a plurality of fuel injection signals to one of the first and second plurality of fuel injectors in dependence on a fuel type command that is indicative of a desired fuel type, said desired fue type being selected from the group comprising liquid fuel and CNG fuel, said injector selector being configured for switching each fuel injection signal after a respective fuel injection event has been completed, said fuel type command being synchronized in accordance with a crankshaft position signal indicative of a crankshaft position.