EGR Vacuum Modulator
NOTE:
When testing EGR vacuum modulator, it will be necessary to monitor engine RPM by using tachometer or scan tester depending on model application. For tachometer or scan tester connections, see IDLE SPEED & MIXTURE
in ADJUSTMENTS article.
- Mark vacuum hose locations and disconnect vacuum hoses from EGR vacuum modulator. Block ports "P" and "R" on EGR vacuum modulator. See Figure.NOTE: Ports "P" and "R" are the double ports on side of EGR vacuum modulator. Port "Q" is single port on side of EGR vacuum modulator.
- Apply air pressure to port "Q". See Figure. Air should pass freely through air filter side of EGR vacuum modulator.
- Start and operate engine at specified RPM. See EGR VACUUM MODULATOR TESTING SPECIFICATIONS table. Repeat steps 1 and 2 . Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt. Reconnect vacuum hoses to proper locations.
EGR VACUUM MODULATOR TESTING SPECIFICATIONS
| Application | Engine RPM |
|---|---|
| Avalon | 3500 |