Initial Inspection and Diagnostic Overview

This check is to be performed with the engine coolant temperature at 176 - 205°F (80 - 95°C).

Purge Vacuum Port Location:

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 the vacuum does not respond as specified in the test, it is probable that the throttle body requires cleaning. Refer to FUEL SUPPLY AND INDUCTION SYSTEMS