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05-20-2012 09:00 PM
Re: Runaway Yanmar 2qm15 HELP!

Well, at least you got it running without scattering it. Sounds like there may be a big air leak or it is starving for fuel. Not familiar with the Yanmar injection pump. IIRC, Bosch pumps could move, similar to distributors on gas engines a long time ago. to set the final precise timing. Looks like all those little arm thingies may not be moving properly? Maybe time to take it to a shop for calibration. Maybe it is out of time somewhat?

Paul T
05-20-2012 06:36 PM
Re: Runaway Yanmar 2qm15 HELP!

05-20-2012 06:35 PM
Re: Runaway Yanmar 2qm15 HELP!

Yanmar 2qm15 Injector pump movement problem - YouTube
05-20-2012 06:31 PM
Re: Runaway Yanmar 2qm15 HELP!

05-20-2012 06:27 PM
Re: Runaway Yanmar 2qm15 HELP!

05-20-2012 11:51 AM
Re: Runaway Yanmar 2qm15 HELP!

I was referring to the injector pump (sorry). It has shims that control the height that the injector pistons ride above the cam lobes. Too low and it pumps too much fuel. In my case loosening a little seems to bring the idle down to a normal level. I will get you guys a video
05-20-2012 11:12 AM
Re: Runaway Yanmar 2qm15 HELP!

How about a video of it starting from cold and then up & down the RPM scale?

Paul T
05-20-2012 10:13 AM
Re: Runaway Yanmar 2qm15 HELP!

The timing marks appear to be right? Not sure about your description of the "pump". Lift pump or injector pump? Can't figure out what loosening it would do. Is the oil level correct? Is it contaminated with fuel? If the blowby is excessive it may be "feeding" the engine extra fuel. Before pulling the pistons I suggest you do a compression test.
Will it idle down and continue to run? Does the injector pump move to effect fine timing settings? If so, it may be off. If the lift pump is suspect you might try a gravity feed fuel source like an outboard gas can.

Paul T
05-19-2012 10:55 PM
Re: Runaway Yanmar 2qm15 HELP!

Here's a picture
05-19-2012 10:39 PM
Re: Runaway Yanmar 2qm15 HELP!

Finally got out to the boat today. Took off the gear cover and tried to set cylinder one (Fly wheel side) to TDC. The timing mark lands 180 degrees away from the cam gear. So there is no way that the timing marks on the cam gear could ever align with the drive shaft in this configuration. So i realigned the timing marks "o"s to "o"'s on both the cam and crank shaft. This puts the front gear side to TDC. Put everything back together again. Started the engine and was running at a high RPM. Resolved to loosen the bolts on the fuel pump. I was able to get the RPM to a normal range. However, the RPM was surging up and down and the throttle response seemed sluggish. Might be because fuel pump wasn't sealed and was either loosing vacuum or vibrating too much. It' still seems to have blow by and smoking allot. There was an oil film in the water. So I think I have two problems; first I need to shim the pump and second I need to pull the pistons to see if I have a ring stuck or something. Once again any of your thoughts are appreciated!
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