Vehicles With Manual Transmission

Fig. 6 EGR system diagram (vehicles with manual trans.):

1. Check the vacuum hose for routing and installation.
2. Cold start and run the engine at idle speed.
3. Check to ensure that increasing engine rpm (idle to 2,500 rpm) does not cause the secondary EGR valve to operate. If the secondary EGR valve operates, replace the thermo valve `B'.
4. Warm up the engine until the coolant temperature exceeds 55 degrees C or 131 degrees F.
5. Verify that when engine rpm is increased as described in step 3 that the secondary valve operates. If it does not operate, inspect the EGR control valve or thermo valve `B'.
6. Disconnect the green striped hose from the thermo valve `B' and apply vacuum. If it is not possible to create a vacuum the thermo valve is operating properly.
7. Disconnect the green striped hose from the nipple of the carburetor.

Fig. 22 Dual EGR valve (testing):

8. Connect a vacuum pump to the green striped hose, Fig. 22.
9. While opening the sub EGR valve by pulling it by hand, apply 20 kPa (5.9 in. Hg) vacuum with a vacuum pump.
10. If the idling speed becomes unstable, the secondary valve is operating properly. If the idling speed remains unchanged, the valve is not operating. Verify that the EGR port is not obstructed and if necessary replace the EGR valve.