Operation Fuel System - Toyota 22R-E Service Manual

EG2–160
OPERATION
FUEL SYSTEM
Fuel is pumped. up by the fuel pump, flows through the fuel filter and is distributed to each
injector and cold start injector at a set pressure maintained by the fuel pressure regulator.
The fuel pressure regulator adjusts the pressure of the fuel from the fuel line (high pressure side)
to a pressure 284 kPa (2.9 kgf/crn2, 41 psi) higher than the pressure inside the intake manifold,
and excess fuel is returned to the fuel tank through the return pipe. When the engine is hot, the
fuel pressure is increased to control percolation in the fuel system and improve restartability and
idling stability.
The pulsation damper absorbs the slight fluctuations in fuel pressure caused by fuel injector from
the injector.
The injectors operate on input of injection signals from the ECM and inject fuel into the intake
manifold.
When starting, the cold start injector operates when engine coolant temperature is less than 70S
C, injecting fuel into the air intake chamber to improve startability.
ENGINE – MFI SYSTEM