Exhaust Gas Recirculation System (EGR)

Fig. 124 Exhaust Gas Recirculation (EGR) Operation, Fuel Injected Models:

1. Make a thorough visual check of system, wiping away oil as necessary to facilitate inspection. Replace any cracked or broken hoses and ensure that all electrical connectors are securely connected.
2. With engine off, check EGR control valve for any indication of binding or sticking by moving diaphragm of control valve upward with finger.
3. Start engine to check EGR control valve and thermal vacuum valve for normal operation, Fig. 124..
4. When engine coolant temperature is low, ensure EGR control valve does not operate when engine speed is increased from idling to 3000-3500 RPM. Place a finger on EGR control valve diaphragm to check for valve operation.
5. When engine coolant temperature is high, ensure that EGR control valve operates when engine speed is increased from idling to 3000-3500 RPM.
6. If EGR control valve does not operate in step 5, check applicable system components.