Fig. 21-13 No. Nomenclature Inspection
1 4 Cover Assembly Ignition Coil Inspect for security of lead assembly to cover. Ignition cable, grommet, terminal and connector for carbon tracks, cracks or distortion. Repair or replace for any of the above conditions. Inspect for broken bakelite, carbon tracks, oil leaks, and dents in coil cover. Replace for any of the above conditions.
INSPECTION OF IGNITION UNIT.
Inspect components as directed in Chart 2103 and Figure 21-13.
— Note —
Replace any component that fails to meet checks listed in Chart 2102.
CYCLING SWITCH AND LIMIT (OVERHEAT) SWITCH. (Refer to Figure 21-18)
1. Removal:
A. If the limit switch is damaged or defective, disconnect the three electrical leads from the switch terminals. Be sure to mark the leads for proper reassembly. (The switch terminals are identified by numbers “1”,“2” and “3”).
B. Remove the two attaching screws and lift the limit switch and spacers (gaskets) from the jacket opening.
C. If the cycling switch is damaged or defective, disconnect the electrical leads being sure to mark them for proper reassembly.
D. Remove the two screws and lift the cycling switch from the jacket opening.
— Note —
No attempt should be made to repair either of these switches. If they do not operate properly, they should be replaced.
2. Installation: (Refer to Figure 21-18)
A. Install the limit switch and spacers (gaskets) by placing them in position in the heater jacket pening and installing two screws.
B. Tighten screws securely; then reconnect the electrical leads in accordance with markings made during disassembly. (Refer to wiring diagram, Figure 21-7)
C. Install the cycling switch (refer to Figure 21-18) by placing it in position in the heater jacket opening and securing it with the two screws. Tighten screws securely; then reconnect the electrical leads to their respective terminals as marked during disassembly. (Refer to wiring diagram, Figure 21-7)
21-40-00 Page 21-33 Revised: February 28, 2002
COMBUSTION AIR PRESSURE SWITCH. (Refer to Figure 21-18)
1. Removal:
A. Disconnect electrical leads from the terminals of the combustion air pressure switch, being sure to mark them for proper reassembly. Disconnect the tube from the switch cap. Exercise caution not to exert excessive bending of the tube. (It is “tacked” to the combustion chamber inside the jacket.)
B. Unscrew and remove the combustion air pressure switch from the fitting on the combustion air inlet tube.
2. Installation:
A. Install the combustion air pressure switch by rotating it on the threaded fitting of the combustion air inlet tube and tighten it securely. Exercise caution not to over-torque the switch as this could change the setting.
B. Connect electrical leads to their respective terminals in accordance with markings made during removal. If in doubt regarding proper connections, refer to the wiring diagram, Figure 21-7. Connect the tube to the switch cap.
C. Check for proper heater operation.
FUEL REGULATOR AND SHUTOFF VALVE. (Refer to Figure 21-4.)
The fuel regulator and shutoff valve is located on the upper right side of the forward bulkhead assembly. Access is obtained by lowering the nose cone.
REMOVAL OF FUEL REGULATOR.
1.
Ascertain that the left fuel tanks are empty and the fuel selector controls are in the OFF position.
2.
Gain access to the regulator and disconnect the electrical leads from regulator and shutoff valve.
3.
Disconnect the fuel line from the outlet port and remove the regulator from the heater fuel pump. Cap all open fuel lines to prevent contamination.
ADJUSTMENT OF FUEL REGULATOR.
The fuel regulator and shutoff valve used in this system is adjustable but not repairable. The following steps cover the proper adjustment of this unit:
1.
Install the regulator in a test stand similar to that shown in Figure 21-14.
2.
Install a 2.0 gph nozzle (Janitrol Part No. C08D09). Gasoline or Stoddard solvent can be used for testing.
3.
Apply fluid pressure from fuel pump and energize the solenoid. Outlet pressure should be 7.0 ± .5 psi, if not, correct accordingly.
4.
Using a screwdriver, break the seal over the adjustment screw and adjust the regulated outlet pressure to
7.0 +/- .5 psi. (Turn clockwise to increase pressure or counterclockwise to decrease pressure.)
5.
De-energize and energize the solenoid at least twice. The outlet pressure should be 6.5 to 7.5 psi with the solenoid energized. When the solenoid is de-energized, the pressure should drop to zero and the fuel now from the nozzle should stop.
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