Exhaust Gas Recirculation: Testing and Inspection

FUEGO
1. Ensure coolant temperature is below 113°F.
2. Start engine and run at idle.
3. Increase engine speed while observing EGR control valve.
4. If valve opens, replace thermal switch.
5. Allow engine to run until it reaches normal operating temperature.
6. Accelerate engine while observing EGR control valve.
7. Valve should open within 5 to 6 seconds.
8. Connect ohmmeter between terminals of pressure surge valve.
9. With transmission in 5th gear and clutch disengaged, accelerate engine.
10. If EGR control valve opens, replace 5th gear contact on manual transmission.
11. With engine at idle, there should be resistance. If there is no resistance, replace surge valve.
12. Shut off engine and ensure resistance drops to zero approximately 6 seconds after engine has stopped.
13. If resistance does not drop to zero, check connection at vacuum reservoir.
14. If connection is satisfactory, replace surge valve.
15. If resistance still does not drop, replace vacuum reservoir.
16. If results in steps 1 through 15 were satisfactory, test is complete.
17. Connect ohmmeter between terminals of thermal switch with engine at operating temperature.
18. If there is resistance, replace thermal switch.
19. Connect ohmmeter between terminals of 5th gear switch.
20. If there is resistance in 1st through 4th gear, or no resistance in 5th gear, replace 5th gear switch.
21. Stop engine and disconnect hose between solenoid valve and throttle housing.
22. Apply vacuum to solenoid valve.
23. If vacuum does not remain steady, check hose connections and repair as necessary.
24. If vacuum still drops, replace solenoid valve.
25. Apply vacuum to solenoid valve while energizing solenoid valve with battery voltage.
26. If EGR control valve does not open, replace EGR control valve or solenoid valve as necessary.
27. Disconnect hose at EGR control valve and repeat step 25.
28. If vacuum does not remain steady, replace solenoid valve.
29. If EGR system still does not operate properly, check wiring and connectors and repair or replace as necessary.