Fuel System - Jeep CJ-3A Owner's Manual

28

FUEL SYSTEM.

FIG. 13—FUEL AND VACUUM PUMP
1—Fuel Pump Bowl
2—Fuel Pump Filtering Screen
3—Fuel Pump Bowl Gasket
4—Fuel Pump Inlet Valve Assembly
5—Fuel Pump Diaphragm Assembly
6—Fuel Pump Diaphragm Spring
7 —Fuel Pump Rocker Arm Spring
8—Fuel Pump Rocker Arm Assembly
9—Fuel Pump Rocker Arm Pin
10—Vacuum Pump Diaphragm Assembly
11—Vacuum Pump Inlet
12—Vacuum Pump Valve Assembly
13—Vacuum Pump Bottom Cover Gasket
14—Vacuum Pump Screen
15—Vacuum Pump Diaphragm Spring
16—Vacuum Pump Bottom Cover
17—Vacuum Pump Lower Housing
16— Vacuum Pump Outlet
19—Pump Housing
20—Vacuum Pump Air Passage Filter
21—Fuel Pump Diaphragm Pull Rod Sea
22—Fuel Pump Valve Retainer
23—Fuel Pump Outlet
24—Fuel Pump Outlet Valve Assembly
The fuel system consists of the fuel tank, fuel lines, fuel pump, carburetor and air cleaner.
The most important maintenance attention is to keep the system clean and free of water, also periodically inspect for leaks.
Should the vehicle be stored for an extended period, the fuel system should be completely drained and the engine started and
allowed to run until the carburetor is emptied. This will avoid oxidation of the fuel, resulting in the formation of gum in the units
of the system.
Gum formation is similar to hard varnish and may cause trouble in the fuel pump valves or the carburetor float valve may become
stuck or the filter screen blocked. Gum formation can be dissolved by acetone, obtainable in most drug stores. In extreme cases, it
will be necessary to disassemble and clean the fuel system, however, often one pint of acetone placed in the fuel tank with about
one gallon of gasoline will dissolve any deposits as it passes through the system with the gasoline.
CARBURETOR.
The Carter carburetor, Model W.O. 636-SA is a precision instrument designed to deliver the proper fuel and air mixtures at all
engine speeds. Carburetor parts wear little; the chief cause of faulty carburetor is the accumulation of dirt and water. More often
than not the carburetor is blamed for poor engine performance when the trouble is elsewhere (See Emergency Chart Page 54). Do
not disturb the carburetor until it is proven that the trouble is not elsewhere. Should it be determined that the carburetor is at fault
consult your Willys-Overland Dealer.
The carburetor is provided with an external adjustment to secure smooth engine idle. Fig. 14, No. 15. To set this adjustment,
proceed as follows:
Make sure that the choke is in a fully open position. Close the idle adjustment by turning it to the right or in against the seat; then
open it one and one-quarter turns. Start the engine and run it until operating temperature is obtained, then turn the adjustment in
or out slightly until the engine