California

These checks are to be performed with the engine coolant temperature at 80 - 95°C (176 - 205°F).

EGR VALVE, CONTROL VACUUM CHECK

EGR Vacuum Port Location:

1. Disconnect the vacuum hose from the throttle body EGR vacuum fitting and connect a hand vacuum pump to the fitting.

EGR Port Vacuum Curve:

2. Start the engine and check to see that, after increasing the engine speed, vacuum raises proportionate to engine speed.

PURGE CONTROL PORT VACUUM CHECK

Purge Hose Vacuum Source:

1. Disconnect the vacuum hose from the throttle body purge hose fitting and connect a hand vacuum pump to the fitting.

Purge Port Vacuum Curve:

2. Start the engine and check to see that, after increasing the engine speed, vacuum remains fairly constant.

NOTE: If there is a problem with the changes in vacuum in either test, it is probable that the throttle body requires cleaning.