Kubota L175 Won't Start

[Grey Tractor Dude]

I have a Kubota L175 that won't start. It was hard cold starting when I bought it a few months ago and now it won't start at all. Can anyone point me to where I can find a manual for this tractor and help point me toward a diagnosis. This is the first diesel tractor I've owned.

What I know:
1. It has fuel.
2. A light on the instrument panel lights when I turn on the key. I'm guessing this is my glow plug light.
3. When I rotate the start switch to the right to engage the starter (after 30 seconds of holding to the left to heat the plugs) the light immediately goes out.
4. When I let off of the key for a few seconds the light comes back on.
5. As the engine is cranking it emits gray smoke, but I don't hear it firing.

I have not done any testing yet. I'm hoping to get outside tonight to test the glow plugs to see if they heat up.
Thanks for reading and for any help you might offer. I'll take it!

 

[xmikew]

Do you pull the throttle about half way toward you before cranking? Does your glow plug indicator glow red after 30 seconds of glowing?

The lights on you panel are charge and oil. They come on when you turn switch to indicate you have connection.

The glow plug indicator is the coil of wire under metal cover with hole on right of panel. It should glow red after you hold start switch left for a bit but mine hardly works.

White or gray smoke usually indicates non fully combusted fuel which does happen when your cylinders are not warm enough.

Definitely check glow plugs.

 

[xmikew]

Also. Since you are grey tractor dude is this a l1500?

 

[xmikew]

http://www.kubotabooks.com/AutoInde...uals/&file=L175 L210 L225 L225DT L260 WSM.pdf

Kubotabooks manual

 

[xmikew]

Oh I just saw your new member post. A l175 is not a gray market tractor. It was made for the us market and has the full support of us kubota dealers. The gray market equivalent would be a l1500.

However some unscrupulous people will relabel gray markets with us equivalents. If it Japanese stickers or writing. It’s gray regardless of what the decals say. Check the serial plate and upload some pics for us to see your tractor

 

[Jstpssng]

Some of the older Kubotas started hard even when they were new. Try holding the glow plugs for longer than seems necessary; I used to count off 30 seconds with my L275 and in cold weather even that wasn't long enough.

 

[JNA]

Follow the linkage from the kill switch to make sure that it is not stuck on kill

 

[Grey Tractor Dude]

I'm stoked to have the manual. Thank you!
I do move the throttle about half way back before attempting to start. I definitely have a grey model and you are right it is an L1500. I got the numbers switched in my mind for which is which (US L175 and Japanese L1500). I was sad to discover the writing on the model plate was in Japanese. I'll upload some pics early tomorrow.
Thanks for decoding the lights for me. I was only guessing what the light on the left was. There is a metal ring on the right next to the tachometer. Is that where the glow plug light should be? There is an empty hole and no light has ever come on that I have noticed.

 

[Grey Tractor Dude]

I have held the switch over for about a minute before and it made not difference. Gray smoke out the stack and never makes a serious attempt to start.

 

[Grey Tractor Dude]

That is definitely worth a try. I'll let you know tomorrow what I found.

 

[petes]

If you've got a voltmeter, check to see that you're getting voltage at the terminals of the glow plugs when holding the key to the left. Should be >5V at each glowplug. If you only get voltage at the first one (closest to the dash) or none then remove / clean / tighten the connection of the wires at the glow plugs, and while they're disconnected, check glow plug impedance with an ohmmeter between the terminal and ground and across the glow indicator (I don't remember what it should read, but definitely less than 10 ohms). The glow indicator is in series (in between) the keyswitch and the glowplugs. The glowplugs are all in parallel. If connections are loose the glow indicator on the dash won't glow or will glow very dimly, the glowplugs won't get hot enough and your engine won't start while cold, just crank and puff white "smoke" (unburned fuel).

 

[WranglerX]

If you've got a voltmeter, check to see that you're getting voltage at the terminals of the glow plugs when holding the key to the left. Should be >5V at each glowplug. If you only get voltage at the first one (closest to the dash) or none then remove / clean / tighten the connection of the wires at the glow plugs, and while they're disconnected, check glow plug impedance with an ohmmeter between the terminal and ground and across the glow indicator (I don't remember what it should read, but definitely less than 10 ohms). The glow indicator is in series (in between) the keyswitch and the glowplugs. The glowplugs are all in parallel. If connections are loose the glow indicator on the dash won't glow or will glow very dimly, the glowplugs won't get hot enough and your engine won't start while cold, just crank and puff white "smoke" (unburned fuel).

Suggest same procedure/solution.... Just late getting here to say it....

Dale

 

[rangerfredbob]

Speaking from some experience from my life with the L260...

Only one of my glow plugs works, front one is open circuit and near onobtanium (I'll look to get one this spring/summer, but it starts for now, I have a link that says they have them). I usually crank a little bit to get fuel in the cylinders then use the glow plugs for a few seconds but it doesn't sound like that is your problem.

I have had fuel starvation problems a couple times, in the banjo bolt going into the primer pump the large bolt is a screen that likes to plug up. I've dealt with that twice. Another time my fuel tank actually plugged so I drained it and blew the chunks out with compressed air.

 

[xmikew]

Thanks for decoding the lights for me. I was only guessing what the light on the left was. There is a metal ring on the right next to the tachometer. Is that where the glow plug light should be? There is an empty hole and no light has ever come on that I have noticed.

It’s not a light per se. It’s a coil of wire that glows red when hot that should be under that metal ring. If there is no wire in there, that might be a problem. Pete’s says glow plug indicator is in series which I think means your glow plugs won’t work if the indicator is missing or loose. Electrical is not my thing though

 

[WranglerX]

This is typical of what a glow plug indicator might be (comes in many different forms though)... As current flows through coil of wire to heat glow plugs it also heats coil of wire in indicator, its like a pilot lamp for a "on/off" switch... If unit is missing (if it originally had one) or damaged or glow plugs (all) have failed you will not get a glow indication that may be indicator of problem...

And if functioning properly may look similar to this...

Also found this circuit to help understand electrical function of glow plug circuit....

You GP circuit may or may not have relay, or "magic timer" it may get power from ignition switch directly to glow plug indicator.... Lots of variations or possibility.... All which depend on tractor brand/model....

Dale

 

[Grey Tractor Dude]

Thank you for all your help. I have 12 volts coming from the glow plug heater switch to the plugs and the plugs checked out bad. I hope I am good to go. Thanks for everything. I'll update after installing and trying the plugs.

 

[Grey Tractor Dude]

Can you tell me why it is said the glow plugs are wired parallel when there is only one wire going to the first plug that is jumped to the second plug?

 

[WranglerX]

Because its next to impossible to wire in series..... Series would be one after the other like those Christmas lights where one goes out and they all go out.....

Parallel mean they each get their power from a common buss and their ground from a common source (head of engine)...



The buss highlighted in yellow is what supplies power to second glow plug, this is what makes GP's in parallel....

Also maybe this graphic will make it clear...

Dale

 

[Grey Tractor Dude]

Yes, that makes sense. Thanks Dale. This has been educational.

 

[Dave M7040]

Because its next to impossible to wire in series..... Series would be one after the other like those Christmas lights where one goes out and they all go out.....

Parallel mean they each get their power from a common buss and their ground from a common source (head of engine)...

View attachment 596878

The buss highlighted in yellow is what supplies power to second glow plug, this is what makes GP's in parallel....

Also maybe this graphic will make it clear...

Dale

In that series of Kubota's: L175, L210, L225, L260 there is one orphan. The GP's on the L210 are wired in series.

This is the series GP which has two electrical terminals on each GP.

This photo is of series wired GP's which someone wired incorrectly

I suggest you start by photographing the GP's and associated wiring on your engine. Because there was one model in that series with series GP, I have found that "do it your self people," get things messed up.
Without properly operating GP's those engines are next to impossible to start.

For engines with parallel GP's, the cost per GP is minimal. The series ones are over $100.


If series GP's were installed by mistake they will not work.

Dave M7040