12431 Mercury PLUG

If the engine is run when there is a problem (malfunction) with the EGR system, be sure to drain the oil from the engine after the problem (malfunction) has been corrected. Install new oil filters and put new oil in the engine.
EGR Systems
Fuel Setting
5P6577 Fuel Setting Tool Group8S4627 Circuit TesterThe procedure that follows, for fuel setting can be done with the housing for the fuel injection pumps either on or off the engine.
Before doing any service work on this fuel system, the outside of the housing for the fuel injection pumps and all parts connected to it must be especially clean.
1. Remove EGR switch cover (1).
REMOVAL OF EGR SWITCH COVER
1. EGR switch cover.2. Install 5P298 Pin (4) in hole. The pin length in mm is given on the large diameter of the pin. Put spring (3) on pin (4) and install 5P6602 Adapter (2).
INSTALLATION OF ADAPTER
2. 5P6602 Adapter. 3. 3J6956 Spring. 4. 5P298 Zero Set Pin (with 17.8507 on it).3. Install 8S7271 Set Screw (6). Remove shut-off solenoid (5).
INSTALLATION OF SET SCREW
5. Solenoid. 6. 8S7271 Set Screw.4. Use wrench (7) and tighten set screw (6) until pin is against pump housing. Install collet clamp (11) in adapter (2). Install indicator (9) and point in collet clamp (11). Loosen nut (10). Move governor control lever (12) to full load position. Make an adjustment to the indicator (move indicator up or down) until both hands are at zero. Tighten nut (10) of the collet clamp. To make a fine adjustment to indicator (9), loosen lock (8). Turn bezel until large hand is on zero and tighten lock (8). Remove set screw (6) with wrench (7).
ADJUSTMENT OF DIAL INDICATOR
2. 5P6602 Adapter. 7. Wrench. 8. Lock. 9. Indicator. 10. Nut. 11. Collet clamp. 12. Governor control lever.5. Release governor control lever (12) and move it to low idle position. Connect the wire clip end of a circuit tester to contact (Z) of EGR switch (15). Put the other end of tester to a good ground on fuel pump. Slowly move governor control lever (12) toward high idle position until light in circuit tester just comes on. Do this several times to make sure of the dimension on indicator (9). This dimension is the fuel setting. For the correct fuel setting, see the RACK SETTING INFORMATION.
CHECK OF FUEL SETTING
9. Indicator. 12. Governor control lever. 13. Fuel setting screw. 14. Locknut. 15. EGR switch. X. EGR contact. Y. EGR contact. Z. Fuel setting contact.6. If the dimension on indicator (9) is not correct, make an adjustment to fuel setting. Loosen locknut (14) and turn screw (13) until dimension on indicator (9) is correct.7. When the adjustment is correct, tighten locknut (14). Check the adjustment by doing steps 1 through 5 again.8. Remove the test tools. Install EGR switch cover (1) and shut-off solenoid (5).Checking EGR Switch
5P6577 Fuel Setting Tool Group8S4627 Circuit TesterInstall test tools and check fuel setting. If necessary make an adjustment to the fuel setting (See Fuel Setting).1. Connect the wire clip end of a circuit tester to contact (X) of EGR switch (3). Put the other end of tester to a good ground on fuel pump. Move governor control lever (2) slowly toward high idle position until light in circuit tester just comes on. Do this several times to make sure of the dimension on indicator (1). Compare this measurement to the CONTINUITY CHECK CHART. See the RACK SETTING INFORMATION for the correct fuel setting.
CHECK OF EGR SWITCH
1. Indicator. 2. Governor control lever. 3. EGR switch. X. EGR contact. Y. EGR contact. Z. Fuel setting contact.2. Repeat above procedure for contacts (Y) and (Z). Compare these measurements to CONTINUITY CHECK CHART.If fuel setting is correct and measurement for contact (X) or (Y) is not correct, inspect load stop pin and replace if necessary. If measurement for contact (X) or (Y) is still not correct, replace EGR switch (3).
EGR SWITCH POSITIONS
X. EGR contact. Y. EGR contact. Z. Fuel setting contact. Voltage Check With EGR Switch Cover In Place
D.C. Voltmeter
EGR SWITCH AND COVER ASSEMBLY
1. EGR switch cover. 2. Bullet connector. 3. Female contact. 4. Male contact. 5. Fuse holder. 6. Wire. 7. Spade terminal.
EGR SWITCH COVER
1. EGR switch cover. 2. Bullet connector. 5. Fuse holder. 6. Wire. 7. Spade terminal. 8. Shut-off solenoid.1. Disconnect spade terminal (7) on wire (6) from shut-off solenoid (8). Remove shut-off solenoid (8).2. Connect a 12 volt D.C. supply to spade terminal (7) on wire (6) from EGR switch cover (1).3. Use a D.C. Voltmeter to measure voltage on the solenoids. Connect the positive (+) lead of the voltmeter to the input of the solenoid. Connect the common (-) lead of the voltmeter to a good ground. The solenoids must be in the circuit. The voltage to the solenoids can be measured at the connection of bullet connector (2). Make a small separation of bullet connector (2) from the other connector. Put the sharp end of the positive (+) lead of the voltmeter against the correct contact (3) or (4) in bullet connector (2).4. With the governor control lever in low idle position, the voltage to the lower solenoid at female contact (3) must show 10 or more volts on the voltmeter. The voltage to the upper solenoid at male contact (4) must show 1.5 or less volts on the voltmeter. The EGR switch, the actuator solenoid voltages, and the EGR valve positions are as shown in Position 1.
(POSITION 1) EGR SWITCH, ACTUATOR SOLENOID VOLTAGES, AND VALVE POSITION AT LOW LOAD
X. EGR contact. Y. EGR contact. Z. Fuel setting contact.5. With the voltmeter connected to the upper solenoid at male contact (4), move governor control lever until the voltage measurement on the voltmeter makes a change from 1.5 or less to 10 or more volts. With the governor control lever still in this position, the voltage to the lower solenoid at female contact (3) must show 10 or more volts on the voltmeter. The EGR switch, the actuator solenoid voltages, and the EGR valve positions are as shown