EGR Functional Tests

The complete EGR system should be inspected and tested at the time intervals recommended by the manufacturer. To assure proper operation of this system all passages and moving parts must operate properly free of deposits, also hoses and connections must be free from leaks. Ambient temperature in the area of the vehicle must be above 68° F for this test.



4-156/2.6L (2.6 Liter) Engines

1. Make sure that vacuum hoses are not leaking and that they are properly routed.
2. With engine cold and idling, increase engine speed to 2500 RPM and make sure that increased engine speed does not cause secondary EGR valve to operate. If it does, replace thermo valve.
3. Allow engine temperature to exceed 149° F, then increase engine speed to 2500 RPM and check that secondary valve operates. If it does not operate, inspect EGR control valve or thermo valve.
4. Disconnect green stripe hose from carburetor and connect a vacuum pump to hose.
5. While opening the sub-EGR valve by pulling it by hand, apply 6 inches Hg vacuum with pump.
6. If idle speed becomes unstable, the secondary valve is operating properly. If idle speed does not change, the secondary EGR valve or thermo valve is not operating. Replace defective component.
7. Disconnect vacuum pump and reconnect hose to carburetor.
8. Disconnect yellow stripe hose from carburetor and connect a vacuum pump to hose.
9. While opening the sub-EGR valve by pulling it by hand, apply 6 inches Hg vacuum with pump.
10. If idle speed becomes unstable, the primary valve is operating properly. If idle speed does not change, the primary EGR valve or thermo valve is not operating. Replace defective component.