G6200 W/D640 Start Problem

[alumley]

Suddenly it's very hard to start and will belch out lots of black smoke before it eventually starts. Once started it runs OK but under the slightest load it will belch black smoke whereas in the past it would only do this under a very heavy load (e.g heavy snow).

Glow Plugs are all good, removed them all and tested, all glow good and when powered one at a time the voltage is 10, when all 3 it's 8 and I think that is normal.

My hunch is that it's either clogged injector(s) squirting fuel or the injector pump is not working properly, maybe a broken spring?

Further diagnosing procedures and other ideas needed before the next snow storm and or mowing season.

Thanks,

Andy

 

[eserv]

Suddenly it's very hard to start and will belch out lots of black smoke before it eventually starts. Once started it runs OK but under the slightest load it will belch black smoke whereas in the past it would only do this under a very heavy load (e.g heavy snow).

Glow Plugs are all good, removed them all and tested, all glow good and when powered one at a time the voltage is 10, when all 3 it's 8 and I think that is normal.

My hunch is that it's either clogged injector(s) squirting fuel or the injector pump is not working properly, maybe a broken spring?

Further diagnosing procedures and other ideas needed before the next snow storm and or mowing season.

Thanks,

Andy

Have you recently bled the injector lines at the injection pump?

 

[alumley]

No, not specifically but I'll give that a try.

 

[eserv]

No, not specifically but I'll give that a try.

It's not that I want you to try it! It is that people often do that and loosen the delivery valves by mistake and the machine runs exactly as you describe! Shouldn't happen on it's own though! ( most of the time they won't admit what they have done so I've learned to approach the problem this way! LOL)

 

[alumley]

Good approach!

Full disclosure: When single digits I had a gelling problem and diesel 911 got me out of that jam. I had to remove the filter assembly and add the 911 50/50 and it started right up. Ever since then it's been this way.

Yesterday I thought about removing the injectors so removed the lines from the injectors but gave up when I learned that getting them out was going to be a real job. Meantime I had removed the rear most line from the pump, and with the electric fuel pump on that squirted out fuel just fine but odd that when I put my finger over it barely a drop came out the ends of the other two lines that were still off the injectors. I buttoned it all back up due to cold toes, tried to start it and while it almost starts.. it doesn't. I know with continued tries and maybe on a warmer day it will start but that's not much help.

Ether didn't help the other day.

 

[eserv]

Good approach!

Full disclosure: When single digits I had a gelling problem and diesel 911 got me out of that jam. I had to remove the filter assembly and add the 911 50/50 and it started right up. Ever since then it's been this way.

Yesterday I thought about removing the injectors so removed the lines from the injectors but gave up when I learned that getting them out was going to be a real job. Meantime I had removed the rear most line from the pump, and with the electric fuel pump on that squirted out fuel just fine but odd that when I put my finger over it barely a drop came out the ends of the other two lines that were still off the injectors. I buttoned it all back up due to cold toes, tried to start it and while it almost starts.. it doesn't. I know with continued tries and maybe on a warmer day it will start but that's not much help.

Ether didn't help the other day.

Just be sure the delivery valves are all tightened down snugly ( The big "bolt" on the top of the injection pump that the injector lines connect to! And please don't use either on a small Kubota engine! Especially one with glow plugs.

 

[Jim L.]

Not saying to do anything, just asking a few questions.

Number of hours and years with this engine?

Air filter and intake clean, filter changed?

Valve lash ever set, how long ago?

When at idle with no smoke, then adding load; does it smoke only on adding load, or keep smoking ever after?

 

[D2Cat]

Good approach!

Full disclosure: When single digits I had a gelling problem and diesel 911 got me out of that jam. I had to remove the filter assembly and add the 911 50/50 and it started right up. Ever since then it's been this way.

Yesterday I thought about removing the injectors so removed the lines from the injectors but gave up when I learned that getting them out was going to be a real job. Meantime I had removed the rear most line from the pump, and with the electric fuel pump on that squirted out fuel just fine but odd that when I put my finger over it barely a drop came out the ends of the other two lines that were still off the injectors. I buttoned it all back up due to cold toes, tried to start it and while it almost starts.. it doesn't. I know with continued tries and maybe on a warmer day it will start but that's not much help.

Ether didn't help the other day.

A couple of points I marked in RED. A diesel injector builds pressure to about 2200# and then "squirts" out the injector tip. Putting any body parts in front of an injector could result in diesel being injecting into you skin. Might want to read up on diesel poisoning. That's for your safety! If you are going to test a spray pattern use a heavy piece of cardboard.

The use of ether can cause your piston rings to fail, bend a rod or other damage to your engine. Best is to solve the starting problem and not try to work around it with starting aids.

Jim and Eserv are directing you to the path of solving your starting problem, but to diagnose it over the internet you need to tell the complete story!!

 

[North Idaho Wolfman]

Good approach!

Full disclosure: When single digits I had a gelling problem and diesel 911 got me out of that jam. I had to remove the filter assembly and add the 911 50/50 and it started right up. Ever since then it's been this way.

Yesterday I thought about removing the injectors so removed the lines from the injectors but gave up when I learned that getting them out was going to be a real job. Meantime I had removed the rear most line from the pump, and with the electric fuel pump on that squirted out fuel just fine but odd that when I put my finger over it barely a drop came out the ends of the other two lines that were still off the injectors. I buttoned it all back up due to cold toes, tried to start it and while it almost starts.. it doesn't. I know with continued tries and maybe on a warmer day it will start but that's not much help.

Ether didn't help the other day.

Let me see if I have this correct...
You removed the rear most injection line from the injector and the injection pump, you turn the key on and without cranking it, it was just pumping fuel out of the injection pump?

If that's what your saying then yes you have a damaged injection pump!
But that in it's self does not sound like what's going on with the cranking and smoking, that would be a broken injector, and or contaminated fuel.

The fact that it happened suddenly leads me to say gasoline or water in the diesel fuel.

 

[alumley]

More details and clarification as requested:

Number of hours and years with this engine?
650 hours, 17+ years that I've owned it, had 25 when I bought it.

Air filter and intake clean, filter changed?
Filter is from 2017 so nearly new. All the intakes are clean

Valve lash ever set, how long ago?
Never touched the valve lash

When at idle with no smoke, then adding load; does it smoke only on adding load, or keep smoking ever after?
Once running it smokes only under a load, and the load is not heavy.

You removed the rear most injection line from the injector and the injection pump, you turn the key on and without cranking it, it was just pumping fuel out of the injection pump?
Correct and all lines were removed from the injectors but only the rear one from the injector pump.

-I have not removed any of the injectors (yet). My finger was over the injector pump rear fitting.

-Ether was an experiment, won't use it again.

-I hadn't touched anything but I had recently added fuel (off road dyed diesel and from the same source I've always used). Before this all started I had observed a lower threshold for smoke under a load. In the past it would only smoke under a very heavy load, think deep wet snow whereas early this winter it seemed like it smoked at less of a load.

What next?

Thank you for all the advice thus far.

 

[Jim L.]

As Wolfman has pointed out, one cause could be fuel that is contaminated or not the right energy content.

I would drain the existing fuel into a container and replace with known good fuel. That is something to do that doesn't require disassembly.

The injection pump and injectors are of concern. It appears to be too much fuel and not enough air for some symptoms.

Along the air path are the valves and their timing.

For now I suggest taking the fuel out of the variables.