FUEL SYSTEM PROTECTION IN A MULTI-FUEL ENGINE

摘要

A method that protects a direct injection fuel injector in a multi-fuel engine comprises selectively operating the engine with at least one of a directly injected fuel introduced through the direct injection fuel injector and a second fuel. When fuelling the multi-fuel engine with the second fuel, a fuel system protection technique is selectively commanded when it is determined that the direct injection fuel injector cooling is required or desirable. The fuel system protection technique comprises (a) suspending fuelling with the second fuel and injecting the directly injected fuel for a first predetermined number of engine cycles, and (b) switching back to fuelling the multi-fuel engine with the second fuel for a second predetermined number of engine cycles. The first and second predetermined number of engine cycles are selected to keep torque disturbances below a predetermined threshold value. Steps (a) and (b) are repeated until it is determined that the fuel system protection technique is no longer necessary.