B2710 Troubles

[jmb9313]

Hi. I'm normally a Deere guy, but I loaned my trailer to a friend to help her move, and when I went by her dad's shop to pick it up, I got cornered and asked if I could work on a B2710 that someone had brought in. Needless to say, that's where I find myself now.
It's a B2710, I was told they replaced the glow plugs, and that it didn't start. I checked all the fuses, it gets 9v to the glow plug rails (glow plugs all bench tested good), we cleaned all the water and debris out of the gas tank and put in new diesel. Found the plug for the rectifier was melted. They put a new fuel filter in and replaced the rectifier and plug and I verified that. I replaced the injectors and lines today, so it is getting fuel. I currently have a wire I connect from the positive batt to the glow plug rail to give them power (once I get it to run, I'll diagnose the electrical). I was told it ran "a week or two ago", found out today that that means last fall. Tractor is not well cared for, oil is dark but not burnt or thick.
It turns over, occasionally you'll hear 1 cylinder fire (and if your real hard on the starter, you might get three), but it won't run under it's own power. I'm not sure how to check the fuel timing, and don't want to tinker with the timing. I'm thinking it could be compression. Thoughts?

 

[sitric]

I would start with compression check. Since you are sure you are getting fuel, and it is fresh, (no water), that is the next logical step

 

[jmb9313]

I would start with compression check. Since you are sure you are getting fuel, and it is fresh, (no water), that is the next logical step

Any idea on what I should be reading when I do the compression check?
And
What would be your next guess if all 4 pass the compression check?

 

[PoTreeBoy]

Is it spinning over rapidly, as opposed to slowly? These things need to crank over smartly. Combined with your glow plug voltage of only 9 volts, it sounds like you may have a bad battery or connection somewhere, especially ground cable to frame.

If the injector pump nor the engine front cover have been removed, the timing won't change. So probably nix that.

Crack the injector lines at the injectors, crank it over until clear fluid appears, then tighten them back.

 

[North Idaho Wolfman]

Did you blead the injector lines?

 

[jmb9313]

Did you blead the injector lines?

Yes.

 

[jmb9313]

Is it spinning over rapidly, as opposed to slowly? These things need to crank over smartly. Combined with your glow plug voltage of only 9 volts, it sounds like you may have a bad battery or connection somewhere, especially ground cable to frame.

If the injector pump nor the engine front cover have been removed, the timing won't change. So probably nix that.

Crack the injector lines at the injectors, crank it over until clear fluid appears, then tighten them back.

I like the way you phrased that, "smartly". Yes, it sounds fair as it cranks. It doesn't sound like it's going too easily, but at the same time, it doesn't sound like the starter is bogged down.

 

[sitric]

Any idea on what I should be reading when I do the compression check?
And
What would be your next guess if all 4 pass the compression check?

minimum is 327psi, and all 4 should be within 10% of each other.

 

[jmb9313]

minimum is 327psi, and all 4 should be within 10% of each other.

Roger, thank you, I will post what I get from it.

 

[Russell King]

Hopefully no starting fluid has been used trying to get it started before you got involved.

The glow plugs are (probably) powered while cranking and also in the glow plug position.

I know on my old L185 that the glow plug sees slightly less than 12 V during the glow position due to a resistor (indicator) and that is bypassed during cranking but the starter is dropping the voltage then.

I think newer models might see less voltage but am not really sure on that one.

 

[kubotafreak]

How much smoke(assuming white) is it making while cranking? If you have cranked it enough to drain the battery and aren't seeing white, you are not getting enough fuel. Where is the throttle during cranking?

 

[North Idaho Wolfman]

With all the electrical issues what's the state of the stop / fuel solenoid.
Some Kubota engines require the fuel solenoid to be activated to start, others require it to be activated to stop.

 

[jmb9313]

It is getting fuel to the cylinders. I don't have to worry if the glow plugs are getting voltage right now because I have them jumped directly to the battery.

It does produce smoke (white) when cranking, not too much, but on lower throttle positions, a little less than I'd like. With throttle at 75% - 100%, it'll fire occasionally, but I've been trying to start it, as per owner's suggestions, at 25% - 50%.

After looking at the weather (rain), I'm not planning on going down to test compression today unless the owner asks me to.

 

[GreensvilleJay]

Generally speaking it is NOT a good idea to directly power the glow plugs from the battery.
You should however disconnect them and check that each is within factory spec ( typically about 0.9 ohms ), but check the specs for yours'.
Also check the manual for how long to apply power to them, based on temperature.