2QM15 spec for testing injection pump for pressure and fuel volume

[aleggert52]

Hello All,
I need the pressure and fuel volume numbers when testing a 2QM15 injection pump at a lab? I am going to the lab again in San Salvador, El Salvador and would like to know the test pressure and fuel volume numbers so I can compare them with the labs testing numbers. Please, if someone knows the numbers please let me know. Thank you.

[skipperpete]

Here are the pages from the Yanmar workshop manual for the pump tech to peruse. I have no idea what the social climate is like in El Salvador but from my experience with fuel injection pump room techs, these guys might be getting a bit hissy about seeing you again with that injector pump so perhaps tread very softly......... unless you’re a good looking blonde, in which case you have unlimited returns.

[Compass790]

Originally Posted by aleggert52

Hello All,
I need the pressure and fuel volume numbers when testing a 2QM15 injection pump at a lab? I am going to the lab again in San Salvador, El Salvador and would like to know the test pressure and fuel volume numbers so I can compare them with the labs testing numbers. Please, if someone knows the numbers please let me know. Thank you.

Its in your service manual, look in the fuel section if I cant paste it here.
Na sorry I cant seem to attach the screenshot. Still reckon injection pump is not likely your problem in itself.
EDIT: Lucky skipperpete knows how to paste the screenshot He posted whilst I was typing.
I'd try his gravity feed earlier suggestion as well just to rule lift pump out.

[aleggert52]

Hello Skipperpete,
Thank you for the information and words of wisdom. I do not want to point fingers at anyone for blame. I just want to fix the injection pump and carry on. It has been a frustrating problem and ongoing for over 6 months. The sooner I can put this problem over the horizon the better. After all patience is a virtue and you can catch more bee's with honey then grief.

[c.K.]

recently I had a fuel delivery problem that was quite persistant all started when I changed the fuel filters
Just found out a couple of days ago that the in fuel line had been twisted beyond my line of sight , possible a contributing factor to my problems

[aleggert52]

Hello c.K.,
Thank you for your reply. I have good fuel flow all the way up to the injection pump.

[skipperpete]

Originally Posted by aleggert52

Hello Skipperpete,
Thank you for the information and words of wisdom. I do not want to point fingers at anyone for blame. I just want to fix the injection pump and carry on. It has been a frustrating problem and ongoing for over 6 months. The sooner I can put this problem over the horizon the better. After all patience is a virtue and you can catch more bee's with honey then grief.

Hi again aleggert52. I just took a google look at the injector pump tech shops in San Salvador.... very classy pump rooms.
So just to clarify.
1. This problem arose very suddenly?
2. The pump has been tested 4 times by a tech?
3. You definitely have a clear, air free supply of fuel at 1 psi or more?
4. The engine starts easily?
5. The engine idles smoothly?
6. No other work preceded this instant change in engine behavior ?
7. The injectors have been serviced since the problem began. ?
8. The rack pin is in the governor yoke?
9. The engine cuts out completely when the speed control is advanced. ?
10. The exhaust system is definitely not blocked?
11. The air intake is clear?
12. The injector hp pipes are not crossed?
13. You have at least reasonable compression on both cylinders.

If all the above were a positive YES and I was the mechanic you hired to fix this, my next move would be to do a brief health check of the engine ..... valve clearances, oil level and condition ( milky, clear or black), exhaust smoke ( black? white? none?) turn off the raw water intake, prepare to block the air intake in case of a runaway. Then operate the governor link to rack pin manually through the link window on the front of the timing cover. If this solves the problem and the rpm can be easily increased with no excessive smoke THEN we can talk about the governor as being the culprit..... very rare but it does happen.
The possibility also exists that the alternator is loading up the engine at low rpm so maybe flick off the belt. If it was this, you would have a lot of soot on the water and the engine would .... maybe cut out.... maybe not.
Good luck with the troubleshooting, I’m looking forward to hearing how you get this fixed.
Pete.

[Compass790]

Good post skipperpete,
Must admit I had given up with no feedback on questions & the realisation that OP has service manual which should be enough to assist him with the problem.
Good onya for persisting & writing a comprehensive series of steps to follow.
Hope you sort it for OP.

[skipperpete]

Haha, thanks Compass790, I’m just about out of ammo and still have no idea why the engine does what it does. I hope the OP finds the solution and let’s us all know.

[aleggert52]

Hello Skipperpete,
Thank you for the information.I will say yes to all but #8. and I will check that. I am totally unfamiliar with the 2QM15 governor I don't even have a clue how it works and the relationship it plays with the fuel and RPM's? When I am able to get the pump back hopefully next week I'll at least have some tests that I can run on it to try and pinpoint the problem being the injection pump or the governor thank to your kind efforts. Yes, Manasa has a very nice facility in San Salvador and so far they have tried to be helpful. I have had the front cover off running the engine and setting the limiter and thought that might be part of the problem having the cover off but it appear it does not seem to matter. I will be spending some time trying to learn how the governor plays a role in the fuel flow and RPM's. If there's any luck I sure could use some of it now. I will keep you in the loop as to the progress that I make. Again thank you for your help!

[Compass790]

Originally Posted by skipperpete

Haha, thanks Compass790, I’m just about out of ammo and still have no idea why the engine does what it does. I hope the OP finds the solution and let’s us all know.

I think you do,
Given that the answer to question 8 was a not sure I skimmed thru Op's first thread "injection pump problem & noted posts 4, 19, 23 & 24.
We shall see.....
Could be wrong but it seems the most likely.

[skipperpete]

Oh Compass.....please let it be that easy. I’m confident that the OP will get that 2QM15 running smoothly in the near future.

[aleggert52]

Hello Skippermate,
#8.The rack pin is definitely in the governor yoke. I had to read it twice to understand the question. Sorry

[Compass790]

It's a pity that the fuel rack not engaged is not your problem as it would have been an easy fix. I assumed that would be it.


Sorry if I'm asking the obvious here but does the fuel rack pin move back & forth correspondingly when you operate the throttle?

[Wotname]

Originally Posted by aleggert52

. I am totally unfamiliar with the 2QM15 governor I don't even have a clue how it works and the relationship it plays with the fuel and RPM's? ............

I will be spending some time trying to learn how the governor plays a role in the fuel flow and RPM's. If there's any luck I sure could use some of it now. .....

The governor doesn't play a big part in the fuel quantity delivery in the 2QM15 although it does (of course) play a small part. I posted the throttle/regulator/governor arrangement in your other thread but I have attached it here as well.

The throttle cable moves regulator lever (item 8) which pulls on the regulator spring (item 9) thus moving the governor lever #2 (item 11). This directly moves the fuel rack (item 13).


The governor (items 5,6&7) only operates the governor lever #1 (item 10) which makes minor adjustments to the fuel rack.

The fuel limiter (item 12) will prevent the fuel rack from opening too far but this is not normally adjusted from manufacture. I suppose it is possible that someone has played with the fuel limiter in the past. Note, it is not part of the injection pump, rather it is part of the engine so it won't have been checked by the injector shop.

If it was me, I would pull an injector but leave it attached to the injection pump. Then decompress both cylinders with the levers and spin the engine over using the starter motor (seacock closed). With the throttle closed (idle), you would expect to see almost zero diesel mist coming from the injector. Then open the throttle to WOT and you would expect to see a substantial volume of diesel mist from the injector. If so, then the throttle lever, fuel rack and injection pump is working correctly. If you don't see any difference in diesel mist between closed throttle (idle) and WOT, work out why!