Diesel Data: Automotive Repair

EGR Vacuum Port Testing

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

EGR Vacuum Inspection:





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 rise in proportion with RPM.

NOTE: If the vacuum does not respond as specified in the test, it is probable that the throttle body requires cleaning.