The Fuel System
(From 2012 Ops notes)
Fuel Supply, Filters & Bleeding: Fuel contamination by dirt rarely causes permanent damage to an engine but can be the cause of poor starting or stalling. Air has a similar effect to dirt but is often easier to diagnose (froth at a bleed screw). Water is the serious contaminant, which can quickly and easily cause permanent damage to the finely machined components of the injector pump and injectors. The golden rule is prevention. The injector system is by far the most expensive and delicate ancillary piece of engineering attached to the diesel engine (£1,000+) and is protected by two of the cheapest items namely the fuel filter and a water separator.
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A fractured low pressure fuel pipe, bridged with plastic hose and jubilee clips (made up section of pipe below the aft berth) forms a repair that will easily get you home providing you can air bleed the fuel system. Follow the procedure set out in the manual. It only takes a few minutes, but remember hand priming the primary pump will only bleed the water separator, fuel filter and injector pump. This may be sufficient to start the engine. If not, to bleed the injectors, (the final stage) the engine must be cranked using the battery.
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Bleeding the Engine: WARNING If you choose to slacken each injector union and bleed the injectors ONE BY ONE, (although not prescribed in the manual, this method will work) the engine will possibly start and run when cranking to bleed the second injector. If not it will most certainly start during the cranking sequence for the third injector. - so whilst bleeding the injectors, avoid loose clothing as well as keeping clear of rotating belts.
Injector Removal: Should it be necessary to remove the injectors, note the differing length of the flange securing-studs. Each injector requires one long & one short securing stud. The longest of the pair will bottom out in the wrong hole.
Fuel Filters: The two original filters use either Perkins P26561117, or Fram C1191PL Filters.
The new filter cartridges are Coopers AZF 090 or Bosch N 4106. The units appear universal so other cartridge fuel filters, of the same size, may well suit.
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April 2006. The fuel supply was modified so as to bypass number one filter, incorporate an auxiliary 20lt fuel tank (stowed in Cockpit aft locker) and installed rubber bulb pump to aid bleeding air from the system. The normal running arrangement is with No 2 valve closed and the auxiliary tank isolated so as to feed fuel via both filters. To avoid confusion and for normal operation No1 valve is tied open.
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In the event of a suspect filter blockage isolating No1 filter and opening No2 valve will feed fuel direct to the second filter.
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If the engine runs with no indication of fuel starvation continue journey.
In the event of continued fuel starvation indicated by continued ‘hunting’ – turn off the engine.
To dislodge any sediment fuel line to the filters, close all auxiliary fuel valves before disconnecting the feed main feed-pipe and blowing back towards the tank. Once clear re-connect the supply and bleed the system.
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Fuel capacity. Whilst the manual refers to 200lt, the usable tank capacity is 170 litres providing, at 2000 rpm approximately 48 hours running giving, in calm weather, a boat speed of 5kn.