Federal

To determine if the internal passages of the throttle body are clear and functioning properly, perform the checks listed below.
These checks are to be performed with the engine coolant temperature at 80 - 95°C (176 - 205°F).

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 this test, it is probable that the throttle body requires cleaning. .