EGR Vacuum Modulator
- EGR vacuum modulator may be a 2-port or 3-port type depending on application. On 2-port models, disconnect hoses from vacuum modulator. Plug one end of vacuum hose connection on EGR vacuum modulator.
- Apply air pressure through remaining port. Air should pass freely through air filter side of modulator. On 3-port models, disconnect all hoses. Block ports "P" and "R". Apply air pressure to port "Q". See Fig 1. Air should pass through the air filter side of modulator freely.
- On all models, operate engine at specified RPM. See EGR VACUUM MODULATOR 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 SPECIFICATIONS
| Application | Engine RPM |
|---|---|
| 2-Port Type (Turbo) | 2500 |
| 3-Port Type | 2500 |