Exhaust Gas Recirculation (EGR) System

Fig. 129 Testing the EGR system:

1. Disconnect the vacuum hose (green stripe) from the carburetor throttle body and connect a hand vacuum pump to the vacuum hose, Fig. 129.
2. Verify that when the engine is cold [coolant temperature less than 45 degrees C (113 degrees F)] vacuum leaks leaks while the engine is operated at 3,500 rpm.
3. Verify that when the engine is warmed up [coolant temperature greater than 95 degrees C (205 degrees F)] vacuum leaks while the engine is at idle and leaks until vacuum reaches about 11 kPa (3 in. Hg) while the engine is held at 3,500 rpm.