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Thanks Paul for your help. The 2QM15 is a pretty simple engine..no glow plugs or turbos or anything. Just fuel, air and combustion (which makes this that more frustrating!). I did take the injector pump and have it rebuilt. Also I did do a garage analysis of the oil. Poured it into a glass jar and let it sit for a few days. There was no visible separation but there was muddy (cabon I assume) at the bottom when I dumped it out. Checking the crank case ventilation hose & housing is on my list of things to check. I'll try running disconnected. Just bought an oil pressure gauge so I'll get some reading on that too. Will also make some temporary injector shims to see if adding additional space will have any impact. I will also pull the head and drop the intake valves to see if I can see any oil residue. Theoretically, it should be dry right? Also ordered a new head gasket. The thought of pulling the engine the third time makes me want to learn to actually "sail" my boat! LOL
Depending on the condition of the engine some blow-by vapors may condense
and be visible in the intake manifold but I wouldn't think there should be puddles of oil anywhere. Intake valves should be fairly clean. If the pump/ governor assembly is all in one housing I guess you can assume it was properly re-built?? If you took out the cam maybe it wasn't re-installed in the right position although some cam drives I have seen are off center so you can only install them in the correct position but the cam marks and crank marks need to be aligned. I think that if the timing was very far off it wouldn't run
at all. The 3 to 4 second "breathing" thing has me puzzled? So far all I can think of is:

1. Bad pump/governor
2. Timing way off
3. Lube oil getting into the intake tract, if that is happening I think the engine would go beyond 3,500 RPM and eventually scatter. If it stops at 3,500 I would suspect the governor/"throttle" linkage or assembly is stuck on "full open"

If you don't have a really good detailed shop manual you should get one, well worth the cost. Let us know what you find. You may have too much faith that the pump was properly re-built? Just a thought?

Paul T
 

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Discussion Starter · #22 ·
You guys are great troubleshooters! However a truly seasoned mechanic would ask the the most relevant questions first. Which should be..........wait for it........ "are you Polish by chance?" which I would respond "why yes I am! How did you know?" Because you have a 2 cylinder engine and you have a 50/50 chance of getting TDC right. Which would be the flywheel side and not the front you idiot!

Yeh I haven't verified it yet but I aligned timing marks on the crank gear with the cam gear based on forward cylinder being #1. It's the rear (flywheel cylinder)! Feeling really stupid at this point but to my defense the Yanmar manual only mentions the TDC orientation once in the entire manual and it's buried inside a paragraph in the middle of the book! I have to say that I have a new new found respect for Yanmar's if they would even start in this scenario! Let you know how it turns out this weekend. Thank god Paul is in California he can't come down to Miami to kick my Ars for waisting 2 two hours of his life!!!
 

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Good on ya, Paul T/Dabnis.. nice job.
 

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You guys are great troubleshooters! However a truly seasoned mechanic would ask the the most relevant questions first. Which should be..........wait for it........ "are you Polish by chance?" which I would respond "why yes I am! How did you know?" Because you have a 2 cylinder engine and you have a 50/50 chance of getting TDC right. Which would be the flywheel side and not the front you idiot!

Yeh I haven't verified it yet but I aligned timing marks on the crank gear with the cam gear based on forward cylinder being #1. It's the rear (flywheel cylinder)! Feeling really stupid at this point but to my defense the Yanmar manual only mentions the TDC orientation once in the entire manual and it's buried inside a paragraph in the middle of the book! I have to say that I have a new new found respect for Yanmar's if they would even start in this scenario! Let you know how it turns out this weekend. Thank god Paul is in California he can't come down to Miami to kick my Ars for waisting 2 two hours of his life!!!
Miamiz & Faster, thanks. I hope that is the problem, easy to fix. It is amazing to me that it would even run that way, let alone run up to 3,500 RPM. Not a waste of time at all, one can always learn from other's experiences. Let us know how it works out.

Paul T
 

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OK, I think I have got it? If you used #2 piston for TDC the timing is 180degrees retarted. Every engine, gas or diesel, that I have worked on uses Piston #1 for TDC settings. Which means:

1. The real intake stroke becomes the power stroke
2. The real compression stroke becomes the exhaust stroke
3. The real power stroke becomes the intake stroke
4. The real exhaust stroke becomes the compression stroke

So what, you ask? The fuel is being squirted in on the intake stroke and eventually accumulates to the point of being enough to ignite on the compression stroke. As the fuel is not all being burned because of the mixed up strokes more accumulates and the engine starts to run away.

I think

Anyway the timing thing is easy to fix, let us know.

Paul T
 

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OK, I think I have got it? If you used #2 piston for TDC the timing is 180degrees retarted. Every engine, gas or diesel, that I have worked on uses Piston #1 for TDC settings. Which means:

1. The real intake stroke becomes the power stroke
2. The real compression stroke becomes the exhaust stroke
3. The real power stroke becomes the intake stroke
4. The real exhaust stroke becomes the compression stroke

So what, you ask? The fuel is being squirted in on the intake stroke and eventually accumulates to the point of being enough to ignite on the compression stroke. As the fuel is not all being burned because of the mixed up strokes more accumulates and the engine starts to run away.

I think

Anyway the timing thing is easy to fix, let us know.

Paul T
Forgot the 3 to 4 second "breathing" thing. Could be that with the valve timing being so far off that on either the intake or compression strokes a valve is partially opening or closing allowing the intake or compression gases to escape very slowly, I think?

Paul T
 

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Discussion Starter · #28 ·
Hey Paul. I keep my boat on a city moring. Went out there on Saturday but they shut down the shuttle boat that takes residents to their boat. 15MPH winds and 1 foot swells and the guy has the nads to call himself a captian! Yeh I chomping at the bit to get out there. Promise to post a followup. EZ
 

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Hey Paul. I keep my boat on a city moring. Went out there on Saturday but they shut down the shuttle boat that takes residents to their boat. 15MPH winds and 1 foot swells and the guy has the nads to call himself a captian! Yeh I chomping at the bit to get out there. Promise to post a followup. EZ
He is probably afraid of being sued if someone got some spray on them:D
Hope it is the timing thing, easy to fix.

Paul T
 

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Great discussion. Miami, hope things get sorted out for you, and the re-timing solves your problems.

A couple of comments based on my own experience with my 2QM15 last year...
First, those shims under the top of your fuel injection pump are critical to its proper operation. If it's shimmed too low, the stroke will be way too long on the pump and it will pump a LOT of fuel at idle. My installed engine's pump has three shims stacked under the top. My spare engine has two shims. Total thickness is 15-20 mils, but that is a high percentage of the total stroke on the pump. If they have been tossed, and not reinstalled, you need to replace them with enough stack height to get the engine back to idle speed with the throttle at idle.

Second, the governor attachment to the fuel injection pump is a PITA and you gotta make sure to get it done right. When I replaced an injection pump last year, it took me about three hours to sort how to hook it up and get it hooked up right. The rack on the pump is a finely tuned, low friction mechanism and if it isn't exactly right, the throttle control and governor will bind, prevent throttle control, and could cause engine speed to run up to max. If I hadn't had the tech manual to puzzle over, I don't think I would ever have gotten it hooked up right. You can't get the governor connected to the rack properly without the top of the fuel injection pump lifted, and you have to settle the top of the pump into place with the rack and governor in the proper position. Once they are in place, you can tighten the top of the pump down, being careful that the governor-rack orientation doesn't shift. Also, did you check the rack adjustment for maximum "throw" and make sure it was properly set?

Won't take but a few minutes to pull the governor inspection cover and check out the governor and injection pump rack. Move the throttle through full throw and see that the mechanism pushes the fuel rack forward smoothly, and that it returns when the throttle is released. I know you had to have the cover off to reinstall the injection pump (didn't you?) and get it hooked up when you replaced the pump, but it might be worth another look.

Good luck.
Will
 

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Discussion Starter · #31 ·
Will, Thanks for the tip. Yes I removed everything from the engine during the rebuild. When I inserted the pump I did make sure the rack ball was inserted in the throttle control assembly. It's hard to say at this point if there are any idle issues or not because I haven't been able to get out there to readjust the timing. However, I lost the position on the stop cable and I'm not sure how to get that in the right position to stop the engine. Also the throttle assembly (spring) seems looser than when I took it off. Not sure if something is screwed up there... Once I get the to the boat I'll have a better idea if I am going to need further help getting the throttle assembly and stop cable adjusted correctly. So I have two shims and will torque to spec but how would I know if the fuel delivery is correct? Thanks for your advice.
 

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Will, Thanks for the tip. Yes I removed everything from the engine during the rebuild. When I inserted the pump I did make sure the rack ball was inserted in the throttle control assembly. It's hard to say at this point if there are any idle issues or not because I haven't been able to get out there to readjust the timing. However, I lost the position on the stop cable and I'm not sure how to get that in the right position to stop the engine. Also the throttle assembly (spring) seems looser than when I took it off. Not sure if something is screwed up there... Once I get the to the boat I'll have a better idea if I am going to need further help getting the throttle assembly and stop cable adjusted correctly. So I have two shims and will torque to spec but how would I know if the fuel delivery is correct? Thanks for your advice.
Sounds like the re-assembly of the pump/governor assembly is tricky business. Suggest one thing at a time:

1. Re-set timing, if it is off as you suspected. If it still runs away:

2. Take pump assembly to a good shop and have them re-calibrate it

Let us know how it works out.

Paul T
 

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Discussion Starter · #33 ·
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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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
 

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Discussion Starter · #37 ·
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
 
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