Exhaust Gas Recirculation: Testing and Inspection

INSPECTION





1. INSPECT AND CLEAN FILTER IN EGR VACUUM MODULATOR
(a) Remove the cap and filter.
(b) Check the filter for contamination or damage.
(c) Using compressed air, clean the filter.
(d) Reinstall the filter and cap.

HINT: Install the filter with the coarser surface facing the atmospheric side (outward).





2. INSTALL VACUUM GAUGE
Using a three-way connector, connect a vacuum gauge to the hose between the EGR valve and VSV.
3. INSPECT SEATING OF EGR VALVE
Start the engine and check that the engine starts and runs at idle.





4. CONNECT TERMINALS TE1 AND E1 OF DLC1
Using SST, connect terminals TE1 and E1 of the DLC1. SST 09843-18020
5. INSPECT VSV OPERATION WITH COLD ENGINE
(a) The engine coolant temperature should be below 55°C (131 °F).
(b) Check that the vacuum gauge indicates zero at 2,500 rpm.





6. INSPECT OPERATION OF VSV AND EGR VACUUM MODULATOR WITH HOT ENGINE
(a) Warm up the engine to above 60°C (140°F).
(b) Check that the vacuum gauge indicates low vacuum at 2,500 rpm.
(c) Disconnect the vacuum hose port R of the EGR vacuum modulator and connect port R directly to the intake manifold with another hose.
(d) Check that the vacuum gauge indicates high vacuum at 2,500 rpm.

HINT: As a large amount of exhaust gas enters, the engine will misfire slightly.

7. REMOVE VACUUM GAUGE
Remove the vacuum gauge, and reconnect the vacuum hoses to the proper locations.





8. INSPECT EGR VALVE
(a) Apply vacuum directly to the EGR valve with the engine idling.
(b) Check that the engine runs rough or dies.
(c) Reconnect the vacuum hoses to the proper locations.

HINT: As exhaust gas is increasingly recirculated, the engine will start to misfire.

9. REMOVE SST FROM DLC1 SST 09843-18020
10. INSPECT EGR VACUUM MODULATOR OPERATION
(a) Disconnect the vacuum hoses from ports P, Q and R of the EGR vacuum modulator.
(b) Block ports P and R with your finger.





(c) Blow air into port Q, and check that the air passes through to the air filter side freely.





(d) Start the engine, and maintain speed at 2,500 rpm.
(e) Repeat the above test. Check that there is a strong resistance to air flow.
(f) Reconnect the vacuum hoses to the proper locations.