Electric Fuel Pump for old 2QM15 Engine

[Paul F]

Last Tuesday after sailing back from Apollo Beach, I turned on the engine heading toward Clearwater Pass. It started fine but after running well for five minutes it stopped seemly starved for fuel. Made it in with a tow. Spent the last week changing out filters and bleeding the lines. No joy. The engine is an old 2QM15 Yanmar. The engine always started and ran well. It seemed like it wanted to start but just could not. A friend with an equally old boat suggested an electric fuel pump. He installed one years ago and had good sucess with it. I gave it a try and what a wonderful improvement. It is so good that I recommend, if you have an older engine with the original lift pump, you consider changing it out. Yanmar is using electric lift pumps on their new engines.

I bought the electric pump from Auto Zone $37. a generic Airtex #E8012S and new fuel lines. The old fuel lines, although not leaking fuel, were way past their lifetime. I bypassed the old mechanical lift pump (cost new $200) because I did not want to worry about fuel leaking through the pump into the crankcase.

Note on fuel line bleeding: The Operations Manual is not correct. Use the steps given in the Service Manual. Link below.

http://www.rambunctiousracing.com/files/2qm15service.pdf

 

[Johnb]

Paul,

I would like to thank you for the link to the manual in PDF format. Although I have a 3 qm30 the section on bleeding is the same and was very helpful.

What effect doe the electric pump have on bleeding? I would guess that with constant pressure bleeding the filter and injection pump would be easier.

John Brecher

 

[Paul F]

Rest of Bleeding Story

Thanks John, I waited on this post until I could say the engine is running again. The electric fuel lift pump works well and makes bleeding a breeze. But, something else happened along the way. The engine would not start the next day and would have to be re bled to make it work. I finally called a mechanic recommended by Yanmar and he suggested venting the return fuel line after the injectors back to the tank rather than the secondary fuel filter. When the fuel returns to the secondary filter the air stays in the system. With the return vented to the tank - route the return higher than the engine - the air in the fuel has a chance to escape out of the system. It seems Yanmar has done this with its later engines. I tried it and after replacing all the washers brass and copper and tightening all fittings the engine has started two days in a row without a problem. Here is hoping it is fixed.