3-18 ENGINE CONTROL SYSTEM
FUEL PRESSURE REGULATOR
The fuel pressure regulator is located in the fuel vapor separator.
The regulator’s function in the system is to maintain a constant fuel pressure relative to the injector while the
engine is operating.
The regulator diaphragm chamber is open to the vapor separator chamber to keep the pressure balanced.
Fuel pressure, adjusted by the regulator, is constantly maintained higher than the pressure in the fuel vapor
separator chamber by approx. 255 kPa (2.55 kg/cm
2
, 36.3 psi).
By-pass fuel is returned back to the fuel vapor separator chamber.
FUEL INJECTOR
The fuel injector is an electromagnetic valve operated by a sig-
nal from the ECM.
When the injection signal is supplied to the fuel injector, the so-
lenoid coil is energized pulling up the plunger.
This opens the injector valve and injects fuel.
Because the fuel pressure is kept constant, the amount of fuel
injected is determined by the amount of time (duration) the valve
is open.
VALVE CLOSED
(below 255 kPa)
VALVE OPENED
(over 255 kPa)
to Fuel vapor separator
chamber
(Fuel return)
from Delivery line
from Delivery line
2
3
4
1
1. Filter
2. Solenoid coil
3. Ball valve
4. Terminal