Engine Controls - System/component Tests: Diagnosis

Engine Controls - System/component Tests: Diagnosis Eagle Summit I

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.

Connect vacuum "T" fitting into Green-striped hose from EGR valve, and connect vacuum gauge to vacuum tee. When engine coolant temperature is 68°F (20°C) or less and engine is idling, snap throttle open to race engine. If no change in vacuum reading is detected on gauge, system is okay.
When engine coolant temperature is 158°F (70°C) or more and engine is idling, snap throttle open to race engine. If vacuum increases to 3.9 in. Hg or higher, system is okay.
Using vacuum pump, apply specified vacuum to open EGR valve. See «EGR VALVE SPECIFICATIONS»(ref-18871-S14159754352000123000000) table. If idle becomes unstable or engine stalls, system is okay.

Disconnect Red-striped purge hose from throttle body, and connect it to hand vacuum pump. Plug nipple on throttle body where purge hose was removed.
With engine coolant temperature at 140°F (60°C) or less and engine idling, apply 14.8 in. Hg. Ensure vacuum is held. Raise engine speed to 3000 RPM and again apply 14.8 in. Hg. Ensure vacuum is held.
With engine coolant temperature at 158°F (70°C) or more and engine idling, apply 14.8 in. Hg. Ensure vacuum is held. Turn engine off. Start engine and within 3 minutes of starting engine, apply vacuum. Ensure vacuum bleeds down.
With engine running for more than 3 minutes after starting, raise engine speed to 3000 RPM and apply 14.8 in. Hg. Ensure vacuum holds momentarily and then bleeds down. NOTE: In step 4), vacuum should bleed down continuously if vehicle is at an altitude of 7200 feet (2200 m) or higher, or if intake air temperature is 122°F (50°C) or higher.