Fuel supply system trouble shooting - Diesel engine fuel supply troubles and remedies

The commonly occurring troubles in the fuel supply systems of automobiles and suitable remedies have been suggested.

High fuel consumption

Air cleaners may be choked, which may be taken out and cleaned by blowing compressed air from the inside of the element. In case the element is too much dirty, it may be washed in a detergent, rinsed and dried.

Fuel may be leaking from somewhere in the supply system, which may be inspected and corrected if detected.

The driver may be in the habit of pumping the accelerator pedal unnecessarily, thus wasting fuel through the accelerating pump.

The idle adjustment may not be correct. If so, the same may be readjusted.

Difficult starting

The carburettor jets may be clogged, which should be removed and serviced.

The choke may not be closing properly while pulled up. The same may be inspected and adjusted.

There may be some air leak into the inlet manifold, which would weaken the mixture which no longer remains sufficiently rich to start combustion. This may be inspected and remedied.

The fuel filter may be clogged and so may not be the same as specified. The pump pressure may be tested as described and if found defective, may be repaired or replaced.

Poor idling

The float level may not be correct, which may be checked and adjusted.

The float valve needle may be sticking. This may be remedied by cleaning the carburettor inlet and valve needle thoroughly.

The screws connecting the carburettor with the induction manifold may be loose or the gasket there may be damaged. In both of these situations, the air may leak into the manifold and weaken the air-fuel mixture.

The jets in the carburettor may be loose, which may be inspected and if detected, tightened.

The air cleaner may be clogged, which may be removed and overhauled.

The throttle valve plate or spindle may be bent, which has to be replaced.

Poor acceleration

The accelerator pump may not be adjusted correctly or may not be working at all. This may be checked when the engine is not running. Just press the accelerator pedal and a spurt of fuel oil should be forced out of the acceleration part in the carburetor. If found defective, the pump including its linkage should be inspected and the defect remedied by repair or replacement as required. Inside the pump, the diaphragm may be punctured or the pump leather washer may have become hard or worn, or the ball check valves may be defective.

The fuel filter may be clogged, which may be cleaned or if required, replaced.

Fuel pump may be defective which may be inspected and repaired or replaced.

The fuel line may be clogged, which may be cleaned.

The fuel level in the float chamber may be low which may be corrected by adjusting the float.

Overheating of the engine

Apart from faulty ignition timing or defective cooling system, this could be also due to a weak air-fuel mixture, the reasons for which have been described above.