I decided to DIY this year's layup and as part of it, change the fuel filter on my Yanmar 3GM30F. Things went pretty well and the use of my son's disposable diapers to catch split fuel worked wonderfully. I plopped the new filter in, reassembled and then went to bleed. After loosening the bleed screw I started to operate the lift pump manually. Having never done this I was/am unsure what to expect wrt feel but I pretty much expected fuel and/or air to come out of the bleed plug. I was disappointed. Nothing at all was happening. The pump lever was pretty limp (I've seen posts talking about spring action and pumping on the up stroke etc but did not experience that at all). After a while I decided to see if anything was happening inside. Nope the bowl/canister was still empty. So I did it up again and tried again. Nothing. The previous owner had installed a priming bulb in fuel line just before the primary filter. I gave that puppy a squeeze and promptly shot fuel all over the place). There was alot of spluttering so I figure the air is out but the lift pump still does not do anything. I don't want to try the engine until I understand the situation. What should I expect from the lift pump? Does it need to be primed in some other way? Is it possible for fuel to come out the output side of the filter and not pass through the filter? (I loosened that connection to see if anything was happening and yes, fuel came out when I squeezed the bulb.) One other observation is that the new filter, while being the correct part number (assured by several sources) is about 1mm shorter, 1mm wider and the metal part of the hole is about 0.5mm smaller than the filter that was in there. Are these sorts of variations normal/acceptable? Thanks Jeff
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S. Sauer
Bleed ing with manual pump
Try rotating the engine 180 degrees by hand using the flywheel with the decompression levers flipped forward to eliminate compression (you don't want to have it kick over). It sounds like the pump lever inside the motor is on the top of the cam lobe, so when you rotate the engine the cam will move and free-up the pump. The owner installed fuel bulb will do the same thing as the manual pump in moving fuel to the filter. Re-check the filter with another from a parts dealer. I have seen mistakes in filing parts with the wrong part numbers, or parts supplier reading the wrong part number for a particular engine. However, the opening in the top of the filter element has a rubber gasket which would appear slightly smaller than a used element. After you have bled all the air out of the new filter and tightened the bleed screw, follow the fuel line from the fuel filter down to the high pressure pump.There should be a 10 mm bleed screw (philips head slot)on the fuel line fitting feeding the pressure pump. Loosen this bleed screw and pump fuel thru until there are no bubbles, then tighten with a 10 mm cresent wrench. Do not over tighten any bleed screws as you can strip the threads, particularly the one at the incomming side of the engine filter which may have a nylon washer. Once the bleed screw washers have been tightened & loosened a couple times you should replace the washers or you will have anoying minor leaks and loose pressure in the system. Buying an engine manual will help with these and other proceedures.
Try rotating the engine 180 degrees by hand using the flywheel with the decompression levers flipped forward to eliminate compression (you don't want to have it kick over). It sounds like the pump lever inside the motor is on the top of the cam lobe, so when you rotate the engine the cam will move and free-up the pump. The owner installed fuel bulb will do the same thing as the manual pump in moving fuel to the filter. Re-check the filter with another from a parts dealer. I have seen mistakes in filing parts with the wrong part numbers, or parts supplier reading the wrong part number for a particular engine. However, the opening in the top of the filter element has a rubber gasket which would appear slightly smaller than a used element. After you have bled all the air out of the new filter and tightened the bleed screw, follow the fuel line from the fuel filter down to the high pressure pump.There should be a 10 mm bleed screw (philips head slot)on the fuel line fitting feeding the pressure pump. Loosen this bleed screw and pump fuel thru until there are no bubbles, then tighten with a 10 mm cresent wrench. Do not over tighten any bleed screws as you can strip the threads, particularly the one at the incomming side of the engine filter which may have a nylon washer. Once the bleed screw washers have been tightened & loosened a couple times you should replace the washers or you will have anoying minor leaks and loose pressure in the system. Buying an engine manual will help with these and other proceedures.
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Sam Lust
What cha got is:....
Your fuel pump is on the high side. No, I don't think it's on drugs. It is driven by a cam inside the engine. If you rotate the engine a bit you will present a lower area of the cam to the pump's follower, and you will get more travel on the priming lever and fuel coming out the bleed hole. Keep pumping till the fuel comes out completely free of air. This may involve quite a bit of fuel. I hope your son hasn't used the diapers prior to this operation, or for that matter won't need them in the near future. The smell of diesel is sometimes difficult to launder out, but with diapers, I'm not sure that's an issue! If you've pumped fuel out the bleeder hole of the filter you have fuel going through the pump. The pump will "prime" itself if it is off the cam and gets enough travel for the diaphram to flex and pump. If you're concerned that the filter is correct pull it off and compare it to the old one. One would expect them to be identical. Compare part numbers and physical attributes, or just go out and buy a new one known to be correct. It is rare but occasionaly an incorrect piece gets through.
Your fuel pump is on the high side. No, I don't think it's on drugs. It is driven by a cam inside the engine. If you rotate the engine a bit you will present a lower area of the cam to the pump's follower, and you will get more travel on the priming lever and fuel coming out the bleed hole. Keep pumping till the fuel comes out completely free of air. This may involve quite a bit of fuel. I hope your son hasn't used the diapers prior to this operation, or for that matter won't need them in the near future. The smell of diesel is sometimes difficult to launder out, but with diapers, I'm not sure that's an issue! If you've pumped fuel out the bleeder hole of the filter you have fuel going through the pump. The pump will "prime" itself if it is off the cam and gets enough travel for the diaphram to flex and pump. If you're concerned that the filter is correct pull it off and compare it to the old one. One would expect them to be identical. Compare part numbers and physical attributes, or just go out and buy a new one known to be correct. It is rare but occasionaly an incorrect piece gets through.
Use the engine to help you pump.
Jeff: It just so happened that I ran my engine out of fuel for the first time since 1987 this weekend. We sailed back to the dock. Got 18 gal. of fuel and started to bleed the system. We used the engine to help bleed the system. Crank it over for about 10-15 sec. with the bleed valve open and then pumped the fuel pump for about 10-20 times and cranked with the engine. We did this 3-4 times and fuel was flowing out of the bleed screw. The worse part was all of the harbor rats givin' their comments and advise.
Jeff: It just so happened that I ran my engine out of fuel for the first time since 1987 this weekend. We sailed back to the dock. Got 18 gal. of fuel and started to bleed the system. We used the engine to help bleed the system. Crank it over for about 10-15 sec. with the bleed valve open and then pumped the fuel pump for about 10-20 times and cranked with the engine. We did this 3-4 times and fuel was flowing out of the bleed screw. The worse part was all of the harbor rats givin' their comments and advise.
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Ed Allen
Start it
a 3 gm will almost self bleed. if you pumped up the bulb as you described the engine will probably self bleed. I has done this several times with great results.
a 3 gm will almost self bleed. if you pumped up the bulb as you described the engine will probably self bleed. I has done this several times with great results.
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Jeff
no luck so far
I tried rotating the shaft to several positions but the lift pump still does nothing. The action is better than I remember (more spring on the return) but still no fuel flows. It is possible that the lift pump is just broken and always has been (boat is relatively new to me). The fuel tank is no far (if at all) below the engine. I was going to try starting it (or at least turn it over with the decompression levers open) but want to be able to watch the engine when I do. Is there someway to run the starter while being at the engine? Also will try putting the old filter back in to see if that is an issue. Thanks for all the quick responses. Jeff
I tried rotating the shaft to several positions but the lift pump still does nothing. The action is better than I remember (more spring on the return) but still no fuel flows. It is possible that the lift pump is just broken and always has been (boat is relatively new to me). The fuel tank is no far (if at all) below the engine. I was going to try starting it (or at least turn it over with the decompression levers open) but want to be able to watch the engine when I do. Is there someway to run the starter while being at the engine? Also will try putting the old filter back in to see if that is an issue. Thanks for all the quick responses. Jeff
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John K Kudera
What to do
Take the filter off again, be sure the gasket is in place, fill the filter with fuel, carefully re assemble to the engine, open the filter's bleed screw, pump the fuel lever til the bubbles cease, then open one of the injector tube fittings, bleed that also. when you get fuel only tighten and the engine should start. The remaining injectors should self bleed in little run time.
Take the filter off again, be sure the gasket is in place, fill the filter with fuel, carefully re assemble to the engine, open the filter's bleed screw, pump the fuel lever til the bubbles cease, then open one of the injector tube fittings, bleed that also. when you get fuel only tighten and the engine should start. The remaining injectors should self bleed in little run time.
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Pete
fuel bleeding
Jeff reading you post and all the answers made me think to remind you to shut OFF the sea water valve when you are trying to spin the engine to start it (to much water will flood it) REOPEN it as soon as it starts on it own ! Another suggestion I have is to prefill the filter bowl with diesel when reinstaiing it. this will eliminate the need for so much pumping of the pump.Given your current state I think I would start all over again and check from the tank all the way to the injectors.You did not mention a primary filter so I'm thinking we are talking about the small engine mounted filter,did you change the (do you have one?)filter between the tanks and the engine?is it blead out? Is there someone "diesel smart" on your dock that could help you? Good Luck and for what it is worth it is most likely nothing big wrong.
Jeff reading you post and all the answers made me think to remind you to shut OFF the sea water valve when you are trying to spin the engine to start it (to much water will flood it) REOPEN it as soon as it starts on it own ! Another suggestion I have is to prefill the filter bowl with diesel when reinstaiing it. this will eliminate the need for so much pumping of the pump.Given your current state I think I would start all over again and check from the tank all the way to the injectors.You did not mention a primary filter so I'm thinking we are talking about the small engine mounted filter,did you change the (do you have one?)filter between the tanks and the engine?is it blead out? Is there someone "diesel smart" on your dock that could help you? Good Luck and for what it is worth it is most likely nothing big wrong.
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Fred Ficarra
Jeff, try this
One of our viewers last summer said to just pull the fuel pump lever a little farther. When it stops moving, that is the beginning of the prime stroke, not the end. I haven't tried it yet. As far as a starter motor activation, check my web site. Click on the thumbnails of the engine.
One of our viewers last summer said to just pull the fuel pump lever a little farther. When it stops moving, that is the beginning of the prime stroke, not the end. I haven't tried it yet. As far as a starter motor activation, check my web site. Click on the thumbnails of the engine.
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Dave
same problem
I had the same problem with the manual primer mechanism. I was told to rotate the engine and still haven't been able to make it work. I primed it by having someone turn over the engine briefly while having the bleeding screws open. If you figure out how to get the manual primer working, please let me know.
I had the same problem with the manual primer mechanism. I was told to rotate the engine and still haven't been able to make it work. I primed it by having someone turn over the engine briefly while having the bleeding screws open. If you figure out how to get the manual primer working, please let me know.
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Paul McGhee
Do what Steve said
Just spin the starter with the bleed valve open. When it spits fuel, close it and repeat for the next one downstream. Works every time. That lift handle is a waste of metal. Paul sv Escape Artist h336
Just spin the starter with the bleed valve open. When it spits fuel, close it and repeat for the next one downstream. Works every time. That lift handle is a waste of metal. Paul sv Escape Artist h336
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J. Tesoriero
Limp lift pump lever
I have to agree with Fred F. It has been my experience that most of the movement of the lift pump lever does nothing. It is only at the very bottom of the lever excursion and only if you apply more pressure, that you actually pump some fuel, That last fraction of an inch does all the work. Alternately, you may have a ruptured pump diaphram. Keep that in mind if the engine does not start/run after the filter change
I have to agree with Fred F. It has been my experience that most of the movement of the lift pump lever does nothing. It is only at the very bottom of the lever excursion and only if you apply more pressure, that you actually pump some fuel, That last fraction of an inch does all the work. Alternately, you may have a ruptured pump diaphram. Keep that in mind if the engine does not start/run after the filter change
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Jeff
Fixed!
Classic. I got professional help (for this and other "issues"). After telling him about the problem we hopped in the boat and he tried it. Sure enough, nothing. He jiggled the camshaft (via the pulleys) and voila, squirting fuel. Sigh. The moral of this is that rotating the camshaft alot is a lottery. You may end up in the same/similar position. Just tweak a bit while pumping. Interestingly, of the two Yanmar-specific and three general diesel books I have, none mention this. Only the internet! Thanks to all. Jeff (with a smooth running 3GM30F)
Classic. I got professional help (for this and other "issues"). After telling him about the problem we hopped in the boat and he tried it. Sure enough, nothing. He jiggled the camshaft (via the pulleys) and voila, squirting fuel. Sigh. The moral of this is that rotating the camshaft alot is a lottery. You may end up in the same/similar position. Just tweak a bit while pumping. Interestingly, of the two Yanmar-specific and three general diesel books I have, none mention this. Only the internet! Thanks to all. Jeff (with a smooth running 3GM30F)
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