Fuel Service Diagnosis - CJ-3B

Fuel system illustration shown for reference only - click here to shop for these parts by interactive diagram

Fuel System Diagram

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Excessive Fuel Consumption: Possible Solution:
Tires improperly inflated Inflate
Brakes drag Adjust
Engine operates too cold Check thermostat
Heat control valve inoperative Check thermostatic spring
Leak in fuel line Check all connections
Carburetor float level high See "Carburetor" section
Accelerator pump not properly adjusted Adjust
Leaky fuel pump diaphragm Replace
Loose engine mountings causing high carburetor fuel level Tighten
Ignition timing slow or spark advance stuck See "Distributor" section
Low compression Check valve tappet clearance
Air cleaner dirty Remove and clean
Engine Hesitates on Acceleration: Possible Solution:
Accelerator pump does not function perfectly Replace piston and rod or adjust
Carburetor float lever Adjust
Spark plugs Replace or clean and adjust
Low compression Check valves
Distributor points - dirty or pitted Replace
Weak condenser or coil Replace
Carburetor jets restricted Remove and clean
Excessive engine heat See "Engine" section
Engine Stalls - Won't Idle: Possible Solution:
Improper condition of carburetor See "Carburetor" section
Low speed jet restricted Remove and clean
Dirty fuel sediment bowl screen Remove and clean
Air cleaner dirty Remove and clean
Leaky manifold or gasket Replace
Fuel pump diaphragm porous Replace
Loose carburetor Tighten flange nuts
Water in fuel Drain and clean system
Improper ignition See "Distributor" section
Spark plugs Clean and adjust
Valves sticking Grind valves

* Learn more about fuel from the Service Manual for Universal Jeep Vehicles page 110