This looks to be a very recently rebuilt engine by a respectable re-builder. I have not yet started the engine as I was doing some re-wiring. I noticed they did eliminate the banjo type fitting and steel fuel inlet line at the fuel filter in favor of a rubber fuel hose. I also see a long rubber fuel hose that seems to come from the fuel pump, but is not connected to anything. I thought it might be some kind of fuel return hose. Anyone have any ideas where this should go?
Yanmar 2GMF20 Mystery Hose
- Thread starter wufibugs
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does your return go from injectors to pump or vice versa?? return line comes from back of the injector fuel rail.....?? could go to injectors or pump.....
I'm a little confused. You say that the fuel line from the pump to the fillter is rubber, is that the one between the filter and the high pressure pump? Or between the lift pump and filter? Which pump is the long rubber hose coming from?
The fuel lines on mine are steel right from the lift pump to the filter then braided hose on to the HP pump. I went out and had a look at mine the only long rubber hose is from the top of the injector back to the fuel tank.
hope this helps
Don
The fuel lines on mine are steel right from the lift pump to the filter then braided hose on to the HP pump. I went out and had a look at mine the only long rubber hose is from the top of the injector back to the fuel tank.
hope this helps
Don
I am sorry for not being clear, Don. OEM is obviously a steel line coming to the fuel filter mounted top left of the engine. It had a banjo fitting. The steel line was disconnected [still left there hanging], and a rubber fuel hose was substituted. I am not sure where that comes from, but my experience with engines in general suggests the route is from pump to filter to injectors. According to the manual I was looking at, the pump runs off the engine. If I have properly located it, looking from the front, it would be low on the block at the left rear. I think the mystery line comes from that left rear area, and seems long enough to circle around to engine somewhere on the right side, but I can't imagine where to. It does not look long enough to be some kind of return line to the tank. I should have isolated the origin of this line, but I ran out of time. It is the only thing holding up the cranking ceremony [besides making a polyurethane cone filter for the cone frame in the air intake housing.]
Peter, it is not the steel line that puzzles me. I suspect they found it easier to work with the flexible hose. Leaving the old one their is either inelegant, or a way to avoid problems with the owner who might have been a purist. It is the other long hose that I am concerned about. When I get back to the boat, I am going to check Zeehag's suggestion that it might go to the fuel rail. I thought I felt around most of the engine for signs of a male hose nipple, but should have been more exhaustive.
Richard, do you have a picture you can post? On these engines the fuel flow goes from the tank to a "transfer" fuel pump to filter to "injector" pump to injectors with a return back to tank off last injector feed. What puzzles me is that they replaced a steel line with a hose. General speaking the steel lines are high pressure and most hose will not hold up very long to high pressure. Looking at the engine from the front the transfer fuel pump is on the lower left. Is it possible the rebuilder left a temporary fuel line to a temporary fuel tank on during a test run ?? My suggestion is to find out what is going on with the steel line as well, just does not seam right to leave a fuel line hanging on engine regardless.
Hi,
Early 2GMs used to return the spill fuel from the injectors to the fuel filter. When the injectors get a little worn there is a tendency for combustion gas bubbles to pass into the spill line so, unfortunately, this resulted in airlocks of the injectors and the engine just stopped, usually at a most inconvenient time - as I discovered to my cost. Subsequently Yanmar provided a free banjo with two pipes to attach to the filter top outlet and this fed the spill fuel back to the top of the tank thus bypassing the filter and overcoming the airlock problem. Not all engines suffered this problem.
I don't fully understand all the descriptions of pipes in the postings above but I would expect the mystery long flexible pipe to be the spill fuel return which needs to go to the top of the tank ABOVE the existing fuel level.
Early 2GMs used to return the spill fuel from the injectors to the fuel filter. When the injectors get a little worn there is a tendency for combustion gas bubbles to pass into the spill line so, unfortunately, this resulted in airlocks of the injectors and the engine just stopped, usually at a most inconvenient time - as I discovered to my cost. Subsequently Yanmar provided a free banjo with two pipes to attach to the filter top outlet and this fed the spill fuel back to the top of the tank thus bypassing the filter and overcoming the airlock problem. Not all engines suffered this problem.
I don't fully understand all the descriptions of pipes in the postings above but I would expect the mystery long flexible pipe to be the spill fuel return which needs to go to the top of the tank ABOVE the existing fuel level.
This IS confusing - there's only two fittings on the lift pump: in and out. In comes from the tank via the primary filter. Out goes to HP pump via the secondary filter. Are you saying there's a third connection to the lift pump? Until you get to the output of the HP pump, neoprene (RATED FOR DIESEL) is ok, and I share the PO's hatred for banjo fittings.
Does sound like a pic would help!
druid
Does sound like a pic would help!
druid
I really appreciate you guys plowing ahead with such inadequate information. When I get back to the boat, hopefully this weekend, I will try to post pictures and be very specific about what goes where. I do not intend to start the engine until this mystery has been cleared up.
In that regard, I have 3 cooling system questions:
1. I rebuilt the impeller [just try and find a replacement brass metric screw that holds the cam in place]. The instructions indicate that it should be "primed" with water. Just how does one go about that?
2. I could find nothing in the manual that indicates what position the seawater seacock corresponds to open and closed.
3. My seawater seacock leads to what appears to be filter with a clear glass housing. I don't know if this was OEM or not. How often should one clean this?
In that regard, I have 3 cooling system questions:
1. I rebuilt the impeller [just try and find a replacement brass metric screw that holds the cam in place]. The instructions indicate that it should be "primed" with water. Just how does one go about that?
2. I could find nothing in the manual that indicates what position the seawater seacock corresponds to open and closed.
3. My seawater seacock leads to what appears to be filter with a clear glass housing. I don't know if this was OEM or not. How often should one clean this?
if it is a proper seacock it should have a "1/4 turn valve" . The handle will turn about 1/4 of a full circle. usually when the handle is inline with the hose the valve will be open. One way to know for sure is to turn it and see if water comes in. The strainer is to catch any material that comes in through the Seacock thats not suppose to got to the water pump. I don't have one but would think that you only need to clean it if it shows "stuff" in it.
Bee
Bee
You are correct, Bee. It is a quarter turn handle, and you confirmed my suspicion that parallel to the hose is open.
It's possible
If I'm not mistaken, these engines have a petcock for draining the block back there close to the lift pump. And they have a hose that goes down to the bilge. Have you checked this out and are sure that it doesn't go to a drain in the block. As was stated by someone else, there should only be an inlet and outlet on the lift pump.
If I'm not mistaken, these engines have a petcock for draining the block back there close to the lift pump. And they have a hose that goes down to the bilge. Have you checked this out and are sure that it doesn't go to a drain in the block. As was stated by someone else, there should only be an inlet and outlet on the lift pump.
I guess the Better phrase would be Parallel to the Valve that the Handle is turning. Not to be confused if the hose makes a 90o turn as soon as it comes off the seacock, open would be in relation to the Seacock / Valve, not the hose itself. I'm sure you already got that part.
Not sure about the priming of the Impeller part. i guess you could remove the hose and pour water down it to fill the impeller and housing, then put the hose back on. Some one else will tell you if i'm wrong but I'm thinking that if you had the impeller out and used a little lube on it and the housing when reinstalling that would give it enough lube till the water got flowing.
Any body ???
Not sure about the priming of the Impeller part. i guess you could remove the hose and pour water down it to fill the impeller and housing, then put the hose back on. Some one else will tell you if i'm wrong but I'm thinking that if you had the impeller out and used a little lube on it and the housing when reinstalling that would give it enough lube till the water got flowing.
Any body ???
- Dec 30, 2009
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It sounds like Petersea may be onto something. Maybe the rebuilder disconected the steel line so he could use a rubber line for a temp return hose possibly back to the fuel can he was using??? Red
I would prime the impeller as Mr. Bee suggests. I'll wait for pictures before I comment on the fuel line issue.
Don
Don
I think with all your questions, you'd do yourself a favor and find a local diesel guy to educate you on the operation, use and maintenance of your engine. Some of your inquiries are pretty basic stuff, that many of us just assume you already know - but don't. Please don't get me wrong, I'm not criticizing you. But find someone at your marina, neighbor or whoever that can walk you through the systems. At some point you're going to either have to do maintenance on the engine or pay someone. Might as well learn something along the way, so you'll know what to do when no one's around or that you're not getting taken for the proverbal "ride". I'd also have the guy that supposedly worked on you diesel to come back and fix the stuff left "dangling". Not a good start. JMHO.
Richard, the clear container you refer to is commonly know as a strainer and it should have a metal screen basket to catch any debris that may get sucked up the water intake. Make a practice of checking every time (daily)you run engine, visual inspection is OK and clean as needed. Check anytime you suspect a raw water flow problem especially if engine is overheating. Along with checking the oil etc etc every time you use the engine (daily). The sea-cock is open when handle is parallel to the sea cock body. As others have said. As far a priming the sea water pump and impeller pour a little soapy water down hose from the heat exchanger and reattach hose. As far as using some lubricationon it I would suggest not unless it is a non petroleum type material. The rubber in the impeller and the petroleum based lube are general not a good match. I am curious to see the pictures with the fuel lines. Will wait until you post to say much more about it but you got a few of us intrigued. Just as a warning when you finally get to start the engine if it does not start with in 20 /30 second of cranking shut the sea cock so the engine does not flood. REMEMBER to open as soon as the engine is running ! ! Keep up updated on your progress ! !
Well, several mysteries are solved. The reason the PO disconnected the metal line from the fuel pump to the filter inlet and substituted a fuel hose is because she had an electric fuel pump installed. I suppose this eliminates most air bleeding operations, but certainly raises a host of problems all its own. The mystery hose was the former Racor to fuel pump hose. I don't know if she was having problems with the original fuel pump. I will have to test is later. I am also guessing that the ugly toggle switch she installed in the panel was for the fuel pump, not the fridge as I originally thought. I added a fuse to that line in the open panel hole, and wired it to what was formerly the switch for the now obsolete Loran. My only reservation is that I don't like wiring 12v stuff on the 120 side of the panel. I understand that new rules now require that they be isolated from one another. Not sure how that would be done, but am searching for the right size plastic boxes to cover the wiring for each side.
Thanks again to all who offered help.
I would be interested to hear your comments on the electric fuel pump. Leave it as is, primary? Make it auxiliary? Eliminate it?
Thanks again to all who offered help.
I would be interested to hear your comments on the electric fuel pump. Leave it as is, primary? Make it auxiliary? Eliminate it?
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