System Testing (Federal)
- Disconnect Green-striped hose from throttle body, and connect vacuum pump to hose end. Plug nipple where hose was connected to throttle body. When engine is cold, 122°F (50°C) or less, and at idle, apply vacuum to disconnected hose. If idle does not change and vacuum bleeds down, system is okay.
- When engine is hot, 205°F (95°C), and at idle, apply 1.8 in. Hg. If idle does not change and vacuum holds, system is okay. Using a vacuum pump, apply 7.7 in. Hg. If idle becomes unstable or engine stalls (and vacuum holds), system is okay.