Toyota 1 MZ–FE Manual page 586

EG2–586
Fuel Pressure Control VSV Circuit
CIRCUIT DESCRIPTION
The ECM turns on a VSV (Vacuum Switching
Valve) to draw the air into the diaphragm chamber
of the pressure regulator if it detects that the temper–
ature of the engine coolant is too high during engine
starting.
The air drawn into the chamber increases the fuel
pressure to prevent fuel vapor lock at high engine
temperature in order to help the engine start when it
is warm.
Fuel pressure control ends approx. 120 sec. after the
engine is started.
WIRING DIAGRAM
1MZ–FE ENGINE – CIRCUIT INSPECTION