Fuel Injector issue?

[Tatheelrod22]

I’m having an issue with my 30 hp Yanmar diesel and its inability to have the throttle cable move the lever attached to it and the engine. Picture below but someone knowledgeable probably doesn’t even need to look at it.

A mechanic who has done some recent work for me on the engine regarding an overheating issue and the heat exchanger tells me that if the cable moves fine which it does, then I have a injector problem and that is a major issue. I took the cotter pin out, detaching it from the arm and it moved freely by hand both there and back at the cockpit shifter.
Does this sound accurate? And by major does anyone venture a guess as to how major?

[Bycrick]

You don’t say specifically which model Yanmar. So, if it were mine:
1. Disconnect the throttle cable. Does the throttle and cable move freely. Completely. No binding at all from end-to-end. With two fingers. If not, you found the problem.
2. Move the lever on the injector pump. Does it move freely? If yes, then make sure that when you reattach the cable that everything is lined up properly. No bending of the cable end.
3. If the injector pump has a problem, ie the arm doesn’t move freely, then I’d guess that something is binding on the shaft. Maybe dirt or minor corrosion. Clean it up as well as you can and apply some penetrating oil. Work the lever back and forth. If that doesn’t loosen it, then you’re going to get into the injector pump.

That’s not a DIY job for most people. On some Yanmar engines it’s a fair amount of work getting the pump off the engine. It’s maybe even more important to get it back on EXACTLY right. Close enough might "appear" to work, but it won’t be right and you can have further problems which can be hard to diagnose. Replacement injector pumps are expensive.

Good luck.

[Tatheelrod22]

Thank you for such a quick reply. It’s a 3 GM 30. The cable moves very freely when disconnected. When off, I cannot budge the arm at all.

[Uncle Bob]

Originally Posted by Tatheelrod22

Thank you for such a quick reply. It’s a 3 GM 30. The cable moves very freely when disconnected. When off, I cannot budge the arm at all.

Hi, try soaking the lever and its shaft with a good penetrating oil, will need multiple applications over a number of days, and keep trying to move the lever, gently. If no luck then a good mechanic is the best way to go.

[Compass790]

Originally Posted by Tatheelrod22

I’m having an issue with my 30 hp Yanmar diesel and its inability to have the throttle cable move the lever attached to it and the engine. Picture below but someone knowledgeable probably doesn’t even need to look at it.

A mechanic who has done some recent work for me on the engine regarding an overheating issue and the heat exchanger tells me that if the cable moves fine which it does, then I have a injector problem and that is a major issue. I took the cotter pin out, detaching it from the arm and it moved freely by hand both there and back at the cockpit shifter.
Does this sound accurate? And by major does anyone venture a guess as to how major?

You may have misheard the mechanic,
You have an injector pump problem not an injector problem.
Agree with other posters, try penetrating oil for a start & it doesn't sound like you have enough mechanical knowledge to mess with the injector pump. You may have a seized fuel rack internally if water has got in your injector pump. I think they are doable if you have good mechanical skills.
Check the CF library for a service manual if you want to look at the problem but if you aren't confident it needs to go to a diesel injection place. I sold a brand new one earlier this year for US $650 but I believe they are over $1000 US from the yanmar agent.
Its possible to clean & free the rack if not too damaged.

[Wotname]

The pictures shows what is inside!

The regulator lever (i.e. the thing that is stuck) attaches to the fuel rack and governor arm by two springs. So it should move a bit regardless of the fuel rack and/or governor.

I suspect it is simply rusted where it goes into the side cover. If you feel confident, remove the side cover and have a look. Be aware of the spring attachment though.

Disregard the coloured circles, they were there for a different explanation.

I would try removing the side cover ad looking before attempting anything with the injector pump.

Even a 'calibrated' tap with a small hammer on the end of regulator lever could break the rust seal and allow it to move again.

I note it is stuck in about the half throttle position. I would try tapping it towards the idle position first. .

[Compass790]

Originally Posted by Wotname

The pictures shows what is inside!

The regulator lever (i.e. the thing that is stuck) attaches to the fuel rack and governor arm by two springs. So it should move a bit regardless of the fuel rack and/or governor.

I suspect it is simply rusted where it goes into the side cover. If you feel confident, remove the side cover and have a look. Be aware of the spring attachment though.

Disregard the coloured circles, they were there for a different explanation.

I would try removing the side cover ad looking before attempting anything with the injector pump.

Even a 'calibrated' tap with a small hammer on the end of regulator lever could break the rust seal and allow it to move again.

I note it is stuck in about the half throttle position. I would try tapping it towards the idle position first. .

Good point Wottie,
Glad you gave a lot better explanation. I forgot it was acting thru the springs.

[Tatheelrod22]

Thanks to all of you and I will try those suggestions. And to the earlier post that said I likely misheard the mechanic, I actually heard him correctly but fail to add “pump” to the post.