System Operational Test

SYSTEM TEST

NOTE: When disconnecting the vacuum hoses, mark or label them to ensure proper routing when reconnecting.

EGR System Check:

COLD ENGINE TEST - Coolant temperature is below 50°C (104°F)
1. Disconnect the green striped vacuum hose from the throttle body and connect it to a hand vacuum pump.
2. Plug the nipple at the throttle body from which the hose was removed.
3. With the engine idling, apply vacuum.
Vacuum should LEAK.

WARM ENGINE TEST - Coolant temperature is above 80°C (176°F)
1. Disconnect the green striped vacuum hose from the throttle body and connect it to a hand vacuum pump.
2. Plug the nipple at the throttle body from which the hose was removed.
3. With the engine idling, apply 1.6" vacuum.
Vacuum should hold and engine rpm should not be affected .
4. Increase vacuum to 7.9"
Vacuum should hold but the engine rpm should change to slightly unstable.
If there is no change in the engine rpm, it is possible that the passages or the valve may need cleaning.