Vacuum Amplifier
- Remove air cleaner and disconnect vacuum line from thermo valve (vacuum amplifier-to-EGR solenoid line from solenoid valve on Calif. B2000 models).
- Connect vacuum gauge to disconnected hose. Run engine at idle and disconnect vacuum amplifier-to-carburetor vacuum line at carburetor.
- Gauge reading should be 1.6-2.4 in. Hg on 626 models and 1.8-2.2 in. Hg on all other models. Slowly increase engine speed to 3500 RPM.
- Gauge should read 3.6 in. Hg. If vacuum amplifier does not respond as outlined, replace vacuum amplifier.