Exhaust Gas Recirculation: Testing and Inspection
PROCEDURE1. Check and clean filter in Exhaust Gas Recirculation (EGR) Vacuum Modulator
^ Remove the cap and filter.
^ Check the filter for contamination or damage.
^ Using compressed air, clean the filter.
^ Reinstall the filter and cap.
NOTE: Install the filter with the coarser surface facing out to the atmospheric side.
2. Install Vacuum Gauge; using a 3-way connector, connect a vacuum gauge to the hose between the EGR Valve and EGR Vacuum Switching Valve (VSV).
3. Inspect Seating Of EGR Valve; check that the engine starts and runs at idle.
4. Using jumper connect terminal TE1 and E1 of the Data Link Connector (DLC) 1. (SST 09843-18020).
5. Inspect VSV operation with cold engine; the engine coolant temperature should be below 55°C (131°F).
^ Check that the vacuum gauge indicates zero at 2.800 rpm.
^ Check that the EGR pipe is NOT hot.
6. Inspect Operation Of VSV And EGR Vacuum Modulator With Hot Engine.
^ Warm up the engine to above 8O°C (176°F).
^ Check that the vacuum gauge indicates low vacuum at 2,800 rpm.
^ Disconnect the vacuum hose from port R of the EGR Vacuum Modulator and connect port R directly to the intake manifold with another hose.
^ Check that the vacuum gauge indicates high vacuum at 3.500 rpm.
NOTE: As exhaust gas is increasingly recirculated, the engine will start to misfire.
7. Remove the jumper from the DLC 1. (SST 09843-18020).
8. Remove vacuum gauge and reconnect the vacuum hoses to their proper locations.
9. Inspect EGR Valve
^ Apply vacuum directly to the EGR valve with the engine at idle.
^ Check that the engine runs rough or dies.
^ Reconnect the vacuum hoses to their proper locations.
^ If no problem is found during this inspection, system is normal; otherwise inspect individual components.