The main purpose of the gasoline fuel injection system is to provide the correct mixture of fuel and air to the cars engine. This mixture must be in proportion to the speed and load placed on the engine. Major components of the fuel injection system include, but are not limited to, the: fuel tank, fuel cap, fuel filter , fuel line, fuel pump, emission controls, injectors, and intake manifold as well as the fuel gauge, which indicates the amount of fuel in the tank.
All fuel injected engines, covered in this section, are equipped with the Toyota Computer Control System (TCCS). The TCCS systems use L-Jetronic, MAP, hot-wire and vortex type air flow meters depending on application.
This integrated control system allows the Engine Control Module (ECM) to control other systems as well as the fuel injection. The control unit consists of a sophisticated micro-processor that receives input signals from many sources and locations on the vehicle. It is capable of rapid calculation of many variables and controls several output circuits simultaneously. This system is broken down into 3 major sub-systems: the Fuel System, Air Induction System and the Electronic Control System. Keeping these divisions in mind will shorten troubleshooting and diagnostic time. An electric fuel pump supplies sufficient fuel, under a constant pressure, to the injectors. These injectors allow a metered quantity of fuel into the intake manifold according to signals from the ECM. The air induction system provides sufficient air for the engine operation. This system includes the throttle body, air intake device and idle control system components.