Yanmar 2QM15 No Start

[KCofKC]

!979 C&C 29' Yanmar 2QM15

History: A friend called and said he was tired of the diesel smell and would I take a look.

I went and it started right up and there was a 1" waterfall behind the canister filter, the cause was obvious, a cross threaded ring that hold the fuel filter in. It has been this way for like 5 years. I removed it, installed a new filter, all looked clean. It took a few trys to get it threaded properly but after about 4 or 5 tries it went and I tightened it up and the engine again started right up. I ran it for about 3 or 4 minutes and shut it off for a couple of minutes, then restarted it, right off. Did this a couple of more times. The owner a couple of days later added 5 gallons of new fuel and left. He returned a couple of days later to sail and it would not start. For some reason he thought it might need bleeding so he unscrewed the two bleeder screws above the injectors. In the process of this he got #1 out and it would not go back in.

I got another call, I went back and tried to screw it in to no avail. I took the return tube off and the cap nuts for #2 and the one at the fuel filter. I tried a different bleed bolt and it went in and the others went into different holes also. I then tried to bleed it, after much cranking no fuel to the injectors. I went back to square one, fuel pump to filter, good flow, fuel filter to injection pump, good flow, flow out of injection pump, nothing, I loosened the top nuts on the injection pump that the lines screw onto and it pumped, #2 stronger than #1. Tightened the top nuts and nothing.

Need some suggestions or past experiences, I don't want to just condemn the injection pump and possibly be wrong.

Suggesstions appreciated.

Thanks in advance,

KC

 

[kloudie1]

SOunds like you still have air in there.. Since the QM injector return goes back to the secondary filter and not the tank, they can be a challenge to bleed.. First bleed the primary filter .. upstream of the lift pump. Next bleed the secondary filter housing by using the lift pump; the bleed screw on the top of the housing. Next bleed the return lines at the connectors on top of the engine injectors. Next bleed the line to the injection pump on the side of the block. No engine rotation to this point except possible slight moves to get the lift pump off cam so the finger lever works full stroke. remember a half turn of crank is a quarter turn of the cam. Now close the seacock and decompress the engine .. spin it with #1 injector feed cracked a little and close it when fuel shows up. Next do #2.. now open seacock and put compression levers in "run" position.. It should start .. once it is running, crack the injector feed line at the injector and bleed a little on each in order.. That should get it.. The order this is done is important because of the return to secondary filter..

 

[KCofKC]

UPDATE

Today I went to the boat and tried to follow the above instructions to a T or at least tried to.

I went to the lift pump to pump the lever, it had little movement, so I rotated the engine and the range of movement was much greater. I pump the little thing about 50 times and never got anything at the inlet line or the bleed screw or the output side of the filter. There never seemed to be much resistance to the lever. I then opened up the inlet hose to the filter and cranked the engine, got good flow, no bubbles, then did the bleed screw on top, again, good flow, no bubbles. Then the outlet line from the filter at the filter, good flow, no bubbles, then the rear injector bleed hole, good flow, no bubbles, then the front or #1 injector, good flow, no bubbles. I then went to the intake side of the injection pump, got very little flow. I then held the hose up and got a weak little spit out of it. I am thinking the injection pump is not getting enough fuel to do it's job, I only got small trickles out of this line, it certainly did not flow enough to fill the line. I got nothing out of the distribution pump nozzles to the lines, so I would not have gotten anything to the injectors.

So that is where I am at. I ran out of time, but I am thinking that either, A the lift pump is inadequate/worn and lacks enough pressure to overcome the resistance of the filter, but it did come out of the filter towards the injection pump. B the hose from the filter to the pump is separated inside or clogged. C, an issue with the new filter.

I will say I have done this on several other engines with out issues, but I also know that this small engine has less flow and would take longer.

Sooooo, further thoughts? And by the way a hearty thanks to kloudie 1

Ken

 

[kloudie1]

Good reasoning, Ken. I would take a close look at the hose from filter to pump.. then all the fun of bleeding starts again. Hang in there, Man.

 

[KCofKC]

Newest Update

I received and installed a new lift pump as well as new fuel filters. Now I have flow to the filter assembly, tightened that one, got flow to the injection pump, this is new, then the filter bleed screw started spitting, tightened this, then the fitting on top of the fuel filter coming in from the return pipe, tightened this, then it spit at #1 & #2 return bleed screws, tightened them. I then went back to the hose feeding the injection pump and got good flow and pressure. At this point, nothing still comes out of the top of the injection pump. I thought that maybe the pipes had to be on so tightened them down and opened up the line at the injectors, nothing. I went back and took the pipes off at the top of the injection pump, again, nothing, so I loosened the fittings on top of the injection pump and got flow, good flow. My conclusion is that when the filter was not screwed in correctly that junk got past the filter and plugged these fittings. They do not look to be user serviceable. I'm hinting that I either need a new injection pump or have it cleaned and serviced. Any other thoughts out there? This is taking for ever and my friend is getting nervous, all thoughts appreciated. Thanks in advance, Ken