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HOMESERVICE MANUALSCHRYSLER1987FIFTH AVENUE 5.2 4REPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMEFC SYSTEMTESTINGWARM DRIVEABILITY TEST 5 - EGR SYSTEM CHECK

1987 Chrysler Fifth Avenue 5.2 4

Warm DRIVEABILITY Test 5 - EGR System Check

1987 Chrysler Fifth Avenue 5.2 4SECTION Warm DRIVEABILITY Test 5 - EGR System Check

With engine at normal operating temperature, let engine idle for one minute. While observing EGR valve stem, raise engine speed to more than 2500 RPM for more than 5 seconds. As engine speed increases, the EGR valve stem should move upward.
If EGR valve stem moves upward, return engine to idle speed. Connect a tachometer. Disconnect vacuum hose from EGR valve. Connect vacuum pump to EGR valve. Very slowly apply vacuum to EGR valve. Engine RPM should drop when 3-5 in. Hg vacuum is applied and continue to drop as more vacuum is applied.
If engine speed drops, proceed to WARM DRIVEABILITY TEST 6 (4-Bbl. models). On 2-Bbl. models, disconnect and plug manifold vacuum hose from the vacuum bleed off valve. Connect a vacuum pump to the bleed off valve and apply 25 in. Hg vacuum. While observing EGR valve stem, raise engine speed to more than 2500 RPM for 5 seconds.

Fig 1: Vacuum Bleed Off Valve
EGR valve stem should NOT move as engine speed increases. If stem does not move, proceed to WARM DRIVEABILITY TEST 6 . If stem moves upward, replace the vacuum bleed off valve. If engine speed in step 2) does not drop, or engine speed does not drop until 5 in. Hg vacuum or more is applied, replace EGR valve.
If the EGR valve stem in step 1) did not move, disconnect vacuum hose from the EGR valve. Connect vacuum gauge to EGR vacuum hose. Increase engine speed to more than 2500 RPM for 5 seconds. Vacuum reading should increase as engine speed increases. If vacuum reading increases as engine speed increases, replace the EGR valve.
If vacuum reading does not increase, on 2-Bbl. models, disconnect and plug EGR signal hose from the vacuum bleed off valve. Reconnect vacuum hose to the EGR valve. Observe EGR valve stem and raise engine speed to more than 2500 RPM for 5 seconds. EGR valve stem should move upward as engine speed increases. If stem moves upward, replace the vacuum bleed off valve.

Fig 2: Vacuum Bleed Off Valve
On Federal 2-Bbl. models, disconnect the vacuum hose from the White side of the EGR vacuum delay valve and connect a vacuum gauge. Increase engine speed to 2500 RPM. Vacuum reading should increase as engine speed increases. If vacuum reading does not increase, go to step 8).

Fig 3: EGR Vacuum Delay Valve
On all models, disconnect bottom hose from EGR vacuum solenoid and connect a vacuum gauge. Raise engine speed to more than 2500 RPM. Vacuum reading should increase as engine speed increases. If vacuum reading increases, repair vacuum hose to EGR valve. If vacuum reading does not increase, remove top hose from EGR vacuum solenoid and connect a vacuum gauge. Increase engine speed to more than 2500 RPM.

Fig 4: EGR Vacuum Delay Valve
Vacuum reading should increase as engine speed increases. If vacuum reading increases, connect a voltmeter to the EGR vacuum solenoid (Gray wire) and ground. Voltage should be within one volt of battery voltage. If voltage reading is okay, replace vacuum solenoid assembly.

Fig 5: EGR Vacuum Solenoid & Ground
If voltage is 0-1 volts, turn ignition off. Disconnect the computer 12-way connector. Turn the ignition switch to the "RUN" position. Voltage reading should be within one volt of battery voltage. If voltage reading is okay, replace the computer. If voltage is still 0-1 volts, repair the Gray wire for a short to ground.
If vacuum reading in step 9) does not increase, on 2-Bbl. models, repair vacuum supply from carburetor. On 4-Bbl. models, disconnect vacuum hose connector from the EGR amplifier. Connect vacuum gauge to middle hose of the connector. Slowly increase engine speed.

Fig 6: EGR Amplifier
Vacuum reading should increase as engine speed increases. If vacuum reading does not increase, repair vacuum supply from carburetor. If vacuum reading increases, connect vacuum gauge to the top hose of the EGR amplifier. Vacuum reading should be manifold vacuum. If vacuum reading is okay, replace EGR amplifier. If vacuum is not okay, repair vacuum supply from the intake manifold.