Vacuum Circuit Test

Fig. 9 Exhaust gas recirculation (EGR) system.:

1. Remove EGR tester and disconnect wire No. 146 from electro valve.
2. Connect a jumper wire from electro valve to ground.
3. Start engine. The electro valve should open, allowing vacuum to flow to the vacuum converter.
4. Disconnect link rod from vacuum converter lever.
5. With engine idling, move vacuum converter lever toward the direction of engine acceleration and check EGR valve diaphragm movement. Diaphragm movement should correspond to the closing of the EGR valve and must operate smoothly.
6. If EGR valve diaphragm does not operate smoothly, check electrovalve operation, vacuum converter operation, EGR valve for a seized condition, for vacuum hose leakage, or improperly routed hoses.
7. If EGR valve diaphragm still does not operate smoothly after performing step 6 above, determine that EGR system is at fault by disconnecting electrical connector C2, Fig. 9. If problem stops, EGR system is at fault, proceed to "Vacuum Converter Test." If problem persists, EGR system is not at fault.