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Hi Guys,
Ancient but bulletproof DG 2.5 litre diesel engine (F50). Wont start without bleeding the fuel system, then only runs for a mile or two before spluttering to a halt, bleeding it again gives a repeat performance. I would expect to find air getting in somewhere between the tank and the lift pump so I changed the whole fuel line but it made no difference. Fuel flows freely when I hand prime so there is no blockage, nevertheless I checked and cleaned the small filter under the banjo of the lift pump but it made no difference. After the lift pump the system is under positive pressure so with the engine running I dont see how enough air could get in to stop it working. Changed the main Fram screw on filter anyway but it made no difference. I'm beginning to think the problem is with the lift side of the pump itself. The inline type injection pump and the lift pump are integral, the lift pump and the plastic primer gadget are mounted on the side of the injection pump, as far as I can work it out everything is conventional, fuel is drawn from the tank to the banjo at the bottom of the lift pump then pumped through the main screw on canister filter to the injection pump, excess fuel from the injectors is returned to the input banjo. Has anyone had one of these pumps apart or know anything about them or have any technical info? Or anyone had similar problems?
Ok it's fixed now, problem
Ok it's fixed now, problem was indeed the lift pump. There are three bolts holding the lift pump to the main injector pump, I was worried about parts falling out but it came away as a complete assembly. Removing the large access cap revealed a spring and the piston which was seized solid. Removing the tappet gives access to the pushrod so I used a 2 leg puller and 3mm steel dowel to force out the pushrod and piston. 1000 grit wet/dry followed by a brillo pad then metal polish has nicely restored both the piston and its cylinder. There are non return valves at the input and output of the pump so I gave gave their seats a good cleaning. Whole job took about 5 hours, pump is now producing 26 psi or thereabouts (measured with an old tyre guage shoved in the end of the pipe!) so up to full spec. Details on the injection pump assembly turned out to be Nippon Denso 22100-87326-000 but no data is available. These pumps are apparently based on or a clone of the Bosche APE style pump and the lift pump itself is called a plunger type (SPA) pump. Some of the old tractor forums have spec, photos and data.
Can't be many people with a DG engine but I hope this info helps in some way.
longdog5.
Hi Assassin, Ah yes, by clone
Hi Assassin,
Ah yes, by clone I didn't mean a 'bootleg' copy, I guess they are made under licence, Nippon Denso seem to have made subtle changes though but at least the Bosch data is close enough.
Regards,
longdog5.
They are not a clone, they
They are not a clone, they are a Bosch pump.