EGR Vacuum Modulator
- On 3-port modulators, 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.
- Operate engine at specified RPM. See EGR VACUUM MODULATOR SPECIFICATIONS table. Repeat previous test procedure. 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 | |
|---|---|---|
| 3-Port Type | ||
| Corolla (4A-F) | 2000 | |
| Pickup (22R) | 3000 | |
| Tercel | 3000 | |