Series Land Rover - Electric Fuel Pump Problems
Electrical fuel pumps were standard fittings on Series I Land Rovers until they were replaced by mechanical pumps. The 6-cylinder Series Land Rover engine however only ever had an electrical fuel pump fitted and all standard diesel engines used a mechanical pump.
If poor engine performance is suspected as being due to insufficient supply of gas then the pump can most effectively be tested by disconnecting the outlet pipe and immersing it in some fuel in a suitable container. Taking due precautions to avoid spillage and nearby sparks or hot surfaces, turn on the ignition and check both the rate of flow of the fuel and if there are any air bubbles present. If there are bubbles and the pump is noisy in operation then there is likely an air leak somewhere between the fuel tank and the pump. Check all fuel lines junctions for security.
If there are no bubbles then a reduced flow rate could be due to several causes:
1. A damaged connecting wire or a poor connection - check all the pump connections and wiring
2. There is a set of contact points accessible by removing the front cover of the pump. If the contact points are dirty or pitted then cleaning with fine abrasive paper may solve the problem temporarily but a new set of contact points will be required.
3. There is a cylindrical gauze fuel filter in the bottom of the pump and if this is partially blocked the pump will tend to run hot and deliver less fuel. The filter is best cleaned in fuel. There is a sediment bowl in the fuel pipe which also has a gauze filter that can be cleaned whilst removing any fuel sediment from the bowl.
4. If foreign matter has entered the pump then it can prevent the efficient operation of the valves. The pump will need to be opened and the valves inspected for tiny particles on their surfaces. A workshop manual can be a help here.
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