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chrisselby
chrisselby

Posted: Fri Apr 22, 2011 10:25am

Post Subject: BMC 1800 engine not starting

Dear Tony I have just completed a full filter and oil change on my engine. I bled the system on the filter housing and the engine started first time and ran as normal for about 15-20 seconds. It then stopped and I haven't managed to get it going since. I rebled the system through to the pump just in case I had an airlock somewhere and double checked that fuel was getting through to the injector pump by loosening the bleed screws on the pump and cranking the engine. I loosened the nuts on the ends of the feed pipes to the injectors and spun the engine, but there was no visible spurt of fuel from any of them. When I changed the fuel filter I did notice that there was quite a lot of sediment in the bowl which I cleaned out before fitting the new filter element. When the engine stopped I did not hear any unusual noises as if something had broken in the injector pump. Is there a simple way of testing if it is a blockage in the plumbing, an air lock in the pump or worse still a dead pump. I would hate to go along the lines assuming it was a pump failure when it was actually something a lot simpler!

Tony-B
Tony-B

Posted: Fri Apr 22, 2011 12:39pm

Post Subject: BMC 1800 engine not starting

BMCs are well known for being a bit of a beast to bleed so I expect all it needs is a good bleed. Before that there are a couple of things to check. First of all turn the fuel tap off and carefully remove the cap from the lift pump. Make sure the rubber O ring stays in the cap. There may or may not be a gauze strainer in there. If so clean it. Clean the sediment trap in the body as well. Replace the cap ensuring the seal is correctly located and the soft washer around the bolt is still soft an din good order. Now check the centre bolt holding the filter together. I expect your filter has a small taper around the top of the centre hole. If so the bolt is sealed by an O ring (more later). If not it uses a soft washer so make sure the soft washer is still soft and in good order. If it is a tapered hole then the O rings supplied with some filters are too small so fit the old O ring and also fit a soft washer under the bolt head. Turn the fuel back on. Now loosen (not remove) the large banjo bolt on the filter head to allow you to bled the filer. Using the priming lever on the lift pump make long low strokes. If most of the lever movement feels slack turn the engine over one revolution. Eventually, after much pumping, air with a few diesel bubbles will come out of the bolt, then half-and-half and eventually fuel with no air in it. At that point tighten the bolt. Now loosen the 8mm headed bleed screw on the cylindrical BODY of the pump â not the one on the âturretâ. Repeat the long slow pumps until AT LEAST 30 seconds after pure fuel comes from the bleed screw. Tighten the screw. After a service this is usually all you need to do but if you do not bleed properly or if you run out of fuel you then need to do the following. Loosen all the large nuts on the injector end of the injector pipes. Make sure the stop mechanism (whatever it is) is set to RUN. Open the throttle to full speed (strictly this should not be necessary but with a sticky governor it can help). Now spin the engine on the starter until flue dribbles or drips from the loose unions. As each starts to drip tighten the union. I bet it will now start but if not come back, I need to know exactly what you found in the filter and lift pump. Tony Brooks PS the injector pump delivers less than a pin head of fuel per stroke so you will never see a spurt from the injector union

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