Circuit/System Description

The fuel injectors are cooled by a calibrated amount of fuel flow through the injector body to the injector return lines. This is referred to as injector return flow leakage. Engine temperature, vehicle load and the fuel type used effect the amount of return flow through the injectors. If the injectors are worn, damaged or contaminated, the amount of fuel flowing through the injector body may increase, resulting in improper injector performance.