Exhaust Gas Recirculation: Testing and Inspection
EXHAUST GAS RECIRCULATION (EGR) SYSTEM INSPECTION1. Inspect and clean filter in vacuum modulator.
a. Remove cap and filter from the vacuum modulators.
b. Check filter for damage or contamination.
c. Clean filter with compressed air.
d. Reinstall cap and filter.
2. Install vacuum gauge.
- Using a 3-way connector, connect a vacuum gauge to the hose between the EGR valve and EGR vacuum modulator.
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 DLC 1.
- Using Special Service Tool (SST) (09843-18020), connect terminals TE1 and E1 of the DLC1.
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 0" 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.
9. Remove SST from DLC 1.
NOTE: If no problem is found with this inspection, system is normal; otherwise inspect each component.