SYSTEM OPERATION The EGR system reduces oxides of nitrogen. This is accomplished by recirculating some of the exhaust gases through the EGR valve to the intake manifold, lowering peak combustion temperatures.
INSPECTION & TESTING 4A-F Engine SYSTEM CHECK
1. Check and clean the filter in the EGR vacuum modulator. Use compressed air (if possible) to blow the dirt out of the filters and check the filters for contamination or damage.
2. Using a tee (3-way connector), connect a vacuum gauge to the hose between the EGR valve and the vacuum modulator.
3. Check the seating of the EGR valve by starting the engine and seeing that it runs at a smooth idle. If the valve is not completely closed, the idle will be rough.
4. With the engine coolant temperature below 122°F (50°C), the vacuum gauge should read 0 at 2,000 rpm. This indicates that the Thermal Vacuum Switching Valve (TVSV) is functioning correctly at this temperature range.
5. Warm the engine to normal operating temperature. Check the vacuum gauge and confirm low vacuum at 2,000 rpm.This indicates the TVSV and the EGR vacuum modulator are working correctly in this temperature range.
6. Disconnect the vacuum hose from the R port on the EGR vacuum modulator and, using another piece of hose,connect the R port directly to the intake manifold. Check that the vacuum gauge indicates high vacuum at 2,000 rpm.
Port R is the lower of the two ports. As a large amount of exhaust gas enters, the engine will misfire slightly at this time.
7. Disconnect the vacuum gauge and reconnect the vacuum hoses to their proper locations.
8. Check the EGR valve by applying vacuum directly to the valve with the engine at idle. (This may be accomplishedeither by bridging vacuum directly from the intake manifold or by using a hand-held vacuum pump.) The engineshould falter and die as the full load of recirculated gasses enters the engine.
9. If no problem is found with this inspection, the system is OK; otherwise inspect each part.
EGR VALVE
1. Remove the EGR valve.
2. Check the valve for sticking and heavy carbon deposits. If a problem is found, replace the valve.
3. Reinstall the EGR valve with a new gasket.
EGR VACUUM MODULATOR
1. Label and disconnect the vacuum hoses from ports P, Q, and R of the EGR vacuum modulator.
Port P is the single port on the one side of the modulator. Port Q and R are stacked, with port Q being on top.
2. Plug the P and R ports with your fingers.
3. Blow air into port Q. Check that the air passes freely through the sides of the air filter.
4. Start the engine and maintain 2,000 rpm.
5. Repeat the test above. Check that there is a strong resistance to air flow.
6. Reconnect the vacuum hoses to the proper locations. jack379633 - 星期二 一月 06, 2009 11:49 am 文章主題:
95NEW卡E,GR不能拆掉或塞住,會亮引擎燈喔.
拆車的應該不貴吧, levin-lu - 星期二 一月 20, 2009 2:27 pm 文章主題: