Yannmar Injector Pump?

[admiralslater]

I am the Owner of a 2003 Outremer45 with 3gm30 engines .the boat sat idle for about 18 months before we got it the engines where fired once and awhile by some one looking after it ,they also worked properly during the inspection and sea trial. They have about 1100 hrs on them. during the refit we had the tanks emptied and cleaned and all filters changed and fresh fuel added .The engines ran well.
After a bouncy trip from Carriacoou to Bequia one engine quit. The bouncing had dislodged some crap from the tank which clogged the the 10 micron racor fuel filter. It ran well for 3 hours during a day trip the next day ,but now starts runs for a while and then cuts out as if it is starved for fuel. I can keep it running by playing the the throttle .with the help of a local engineer these are the steps we have taken
1 pulled p/u tube in tank
2 checked flow from tank to filter
3 checked flow through racor filter
4 checked flow to and through and operation of lift pump
5 checked flow through secondary inline fuel filter on engine
6 checked flow to injector pump
7 bled injector at bleed point
8 checked air intake
all the filters are new and we found no issues right up to the injector pump.

The engineer thinks that it must be an issue with the pump,he did not jump to that conclusion and has no financial interest in it being the pump so please no comments on that as I was with him all the way . I believe something is intermittently blocking the pump and I hope if I keep using the the engine and not allowing it to stall that it may clear other wise it is a big bill .
Does anyone have any other ideas.
WE are in Bequia at the moment so access to the intraweb is spotty so if I don't respond that is why. I know we will get little sympathy given our location
Thanks David
ps if some one had has good luck with a place to get the pump serviced let me know

[dtlx11]

Hi Admiralslater
Just last week I removed the injector pump on my 3gm30, took it all to bits, cleaned and re-assembled. Had the engine running again yesterday. I have very little experience with engines I just worked very closely with the manual and kept all the parts for each pump in seperate containers. Its a bit fiddly but its worth knowing your way around the injector pump incase it goes again.

In my humble opinion, read your manual and then have a go yourself. Save your money and spend it at the next island (I am not ashamed to admit I am quite jealous sitting here in rainy Belgium waiting for spring)

[gah964]

did you take the injector apart?

[dtlx11]

Originally Posted by gah964

did you take the injector apart?

+1, before you remove the injector pump remove your injectors and see if they are blocked. Its far easier than removing the pump.

[admiralslater]

thanks for useful replies ,the boat did not have a manual with it ,would it we be worth while to get an official manual from yannmar? we have not removed the injectors but quite often the engine runs properly and then starts to sputter ,so it seems to meet that if it was an injector perhaps the problem would be more permanent . what does anyone think

[boom23]

You should be able to find the Yanmar User and Service manuals in pdf form on the Internet for free.

Search for "Yanmar service manual pdf 3GM30"

Good luck.

[gah964]

Originally Posted by admiralslater

thanks for useful replies ,the boat did not have a manual with it ,would it we be worth while to get an official manual from yannmar? we have not removed the injectors but quite often the engine runs properly and then starts to sputter ,so it seems to meet that if it was an injector perhaps the problem would be more permanent . what does anyone think

there is a pin inside of the injector that moves up and down with a spring and the parts get sticky or gummed up. Could also be a water leak in the cylinder jacket or head gasket will do this. injector pumps rarely go bad.
I only work on them, but you can go your own way about this.

[dtlx11]

Yanmar GM series service manual Its quite a big file so I advise you to load it then keep the window open

And what follows inevitably, GM series parts list with explosion diagrams

As for the main problem, looking in the above manual under 13.13 'troubleshooting and repair:

Problem: Speed decreases unexpectedly
Causes: Governer maladjusted, Overload, Piston seized, Bearing seized, fuel filter clogged, fuel injection pump or injection valve sticking, dirt in fuel pump delivery valve, air in fuel system or water in fuel system. It goes on to suggest possible solutions.

I think it is more than likely a fuel supply problem, as you suspect. Now there are many options available to try and fix it. I would try the easy ones first which is pulling the injectors. moving through to pulling the injector pump and if it still won't fix it you will just have to start at the fuel tank, replacing if necessary, moving through the entire fuel system to the exhaust manifold checking nothing is blocked, no oil leaks, mixing elbow isn't blocked.

I enclose a picture of my clogged up exhaust manifold and fuel tank which I had to cut out with an angle grinder, upside down, inside the bilge in order to remove. Your boat is much younger than mine (original tank from 1978!) but it made me realize what horrors can be hidden where we can't see.




Good luck

[Schrewsburyduo]

I had a similar problem. Ended up being a small air leak into the system. Make sure you re bleed everything, and that all hoses esp from the racor and the secondary filter are tight. Might do the trick.

[admiralslater]

just a note to all that replied along with lesson learned .

The engine problem seems to be solved and it was all due to an obsolete valve on a day tank that does not exist any more . Suffice it to say that the $%^#!~ thing was in the wrong position and did not let fuel back in the tank. There were two small fuel leaks on the supply side but the engineer said they would not have caused total shut down .
lesson learned
1 remove any unused or unnecessary hoses valves etc from fuel system
2 don't just check the supply side for issues
3 check the small things first
4 make a trouble shooting check list that includes the less obvious possibilities

Thanks again ,now on to the house bank
David

[dtlx11]

Glad you got it fixed. Its normally the simple things, so it was the fuel return line from the injectors back into the tank causing the problem?

[admiralslater]

Well it was not the line really it was a three way valve that used to feed a day tank that was in the wrong postion that caused the problem. I only discovered it because I was taking the valve out and the line going back to the main tank was dry . never introduce un-needed complication to the systems
David