Pickup 4WD L4-2559cc 2.6L SOHC (4ZE1) (1988)
Fuel Pressure Regulator Vacuum Switching Valve: Description and Operation
Canister And Pressure Regulator Vacuum Switching Valve
For improved starting and idle stability, the system raises fuel pressure slightly on hot re-starts. The pressure increase is accomplished by cutting off the
vacuum signal to the fuel pressure regulator. The ECM controls this function through the pressure regulator vacuum switching valve (VSV) when it
senses a hot re-start condition. This VSV is in an assembly together with the canister purge VSV.