Valvula Egr Blazer 95 y363r

1995 Chevrolet Blazer P - EGR FUNCTION TESTING' '1990-95 ENGINE PERFORMANCE General Motors Corp. EGR Function Testing

P - EGR FUNCTION TESTING 1990-95 ENGINE PERFORMANCE General Motors Corp. EGR Function Testing

EGR FUNCTION TESTING PORTED & BACKPRESSURE EGR 1. Install vacuum gauge between EGR valve and carburetor vacuum port. With engine at normal operating temperature, raise engine speed to about 3000 RPM. Vacuum gauge should read at least 5 in. Hg. 2. Check EGR Thermal Vacuum Switch (TVS) operation by installing a vacuum gauge between TVS and vacuum source and noting presence of vacuum with engine running and at normal operating temperature. 3. Turn engine off. Manually depress/push in EGR valve diaphragm. While depressed, hold finger over source tube and release diaphragm. Check for diaphragm and seat movement. Diaphragm should take at least 20 seconds to move to seated position. If not, replace EGR valve. 4. Start engine. Using a hand-held vacuum pump, apply vacuum to EGR valve. EGR valve should open and engine should run rough or stall. If EGR valve does not open, replace EGR valve. If EGR valve opened, but idle quality did not change, clean plugged EGR ports. EGR WITH EVRV CONTROL NOTE:

For additional testing, see EGR/EVRV code tests in appropriate G - TESTS W/CODES article.

Luis Hurtado lunes, 25 de enero de 2010 02:06:44 02:06:31 p.m.

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1995 Chevrolet Blazer P - EGR FUNCTION TESTING' '1990-95 ENGINE PERFORMANCE General Motors Corp. EGR Function Testing

Fig. 1: EGR & EVRV Location (Heavy-Duty Gasoline Models) Courtesy of GENERAL MOTORS CORP. Luis Hurtado lunes, 25 de enero de 2010 02:06:31 p.m.

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© 2005 Mitchell Repair Information Company, LLC.

1995 Chevrolet Blazer P - EGR FUNCTION TESTING' '1990-95 ENGINE PERFORMANCE General Motors Corp. EGR Function Testing

Fig. 2: Servicing EVRV Filter (Heavy-Duty Gasoline Models) Courtesy of GENERAL MOTORS CORP. LINEAR EGR Luis Hurtado lunes, 25 de enero de 2010 02:06:31 p.m.

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© 2005 Mitchell Repair Information Company, LLC.

1995 Chevrolet Blazer P - EGR FUNCTION TESTING' '1990-95 ENGINE PERFORMANCE General Motors Corp. EGR Function Testing

1. Install scan tester. Ensure P/N switch is operating properly. With engine at normal operating temperature, command EGR pintle position to zero percent. Increase engine speed to 2000 RPM. If scan tester reads actual EGR pintle position at greater than 3 percent, EGR valve is stuck open. Replace EGR valve. 2. If scan tester reads actual EGR pintle position at 3 percent or less, command a 25 percent position step increase (i.e. 0-25 percent, 25-50 percent, 50-75 percent, etc.). Observe MAP sensor reading and actual EGR pintle position for 3 seconds. EGR should increase by about 25 percent and MAP reading should also increase. 3. If actual EGR pintle position is stable and within 10 percent position of desired EGR pintle position command after 2 seconds, go to next step. If actual EGR pintle position is not as specified, go to step 5). 4. MAP reading should have increased when EGR pintle responded. If MAP did not respond, check EGR ages and EGR valve for blockage. If MAP responded, set desired EGR pintle position to 100 percent. If EGR pintle position sets to 100 percent, EGR is okay. If not, replace EGR valve. 5. Turn engine off. Check EGR electrical circuit and connecting components. Turn ignition on, check 5-volt reference voltage on harness connector terminal "D" (Gray wire). If 5-volt reference voltage is not present, check ECM. If circuits are okay, replace EGR valve. DIESEL EGR 1. Turn engine off. Disconnect vacuum hose to EGR valve. Connect a hand-held vacuum pump to EGR valve and apply 10 in. Hg. EGR pintle should move up and stay up for at least 20 seconds. If not, replace EGR valve. 2. To check vacuum pump operation, connect vacuum gauge to vacuum inlet (small fitting). DO NOT plug or disconnect outlet fitting. With engine idling, vacuum should be at least 18 in Hg one minute after start. If not, check for belt slippage, vacuum leaks or other obvious defects. If vacuum reading is as specified, replace EGR valve.

Luis Hurtado lunes, 25 de enero de 2010 02:06:31 p.m.

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© 2005 Mitchell Repair Information Company, LLC.