EGR Vacuum Modulator
NOTE:
When testing EGR vacuum modulator, it may be necessary to monitor engine RPM by using scan tool. For scan tool connections, see IDLE SPEED & MIXTURE in ADJUSTMENTS - TURBO
article.
- Disconnect the 2 vacuum hoses from EGR vacuum modulator. Plug port "P" on EGR vacuum modulator. See Fig 1.
- Apply air pressure to port "Q" on vacuum modulator. See Fig 1. Air should flow freely through air filter side of EGR vacuum modulator.
- Start and operate engine at specified RPM. See EGR VACUUM MODULATOR TESTING SPECIFICATIONS table. Repeat test procedures in 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 |
|---|---|
| Turbo | 3500 |