Glow plug wiring? L200 / L210

StorminN

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Aug 31, 2010
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Washington state, USA
Hi guys,

The L200 I recently bought hasn't started well since I got it... it seemed like it was trying to start on only one cylinder (and it only has two, so that's not good!)... I assumed one glow plug was dead. Of course it was 60F when I bought it, so I could get it to start eventually... but now it's 38F here, and it won't start at all.

This week, I spent some time looking and finally found one glow plug ($48 after tax & shipping!!) at a dealer an hour and half away, and got it via UPS yesterday... I put it in today, and the tractor acts the same... still doesn't want to start... so I took the two glow plugs out, wired them up where I could see them, and for some reason, I can only get one to glow at a time.

At first, I didn't realize that the body of the glow plug that screws into the head is not the (-) ground of the plug... every other diesel I've ever worked on uses the body of the plug as the ground, and you just wire a positive to the top of the plug. But, in testing the glow plugs out of the head, I figured out the way these NGK's are designed, with the threaded body of the plug insulated from both the positive and negative parts of the plug... different!

I don't think the glow plugs in this tractor have been wired right for a long time... at least not for its last owner... but now I've got them wired with separate grounds and positives now, everything in parallel... and I still can only get one to glow at a time... it's almost as though the two glow plugs have different resistances, and only one is actually glowing... the other gets warm, but no glow.

This L200 has a glowplug indicator (resistive coil) in the dash... it glows bright after about 6-7 seconds... and from there, a #10 wire runs down to a big coil resistor that sits under the fuel tank... which starts to glow after about 20 seconds. From there, a #10 wire runs to the first glow plug, then jumps over to the second. The second glow plug has a #10 wire going to ground, on the head.

With everything wired up, and a fresh battery, I'm only reading about a volt and a half between the top of the glow plugs and ground, when the glow plug switch is on. I'm getting 12V to the upstream (dash) side of the big coil resistor. If I bypass the big coil resistor, and supply 12V to the + of the glow plugs, I can get the glow plugs to glow better, but I'm afraid they might burn out – and at $48 each, I don't want to burn any out. (!)

So... I've been scratching my head... I made sure all the wires from the coil resistor to the plugs and to ground were cleaned and good, and even got ridiculous at one point and used some #6 copper in parallel on the plugs, thinking the 40 year old, maybe #10 aluminum wire might be the culprit!

So my questions are... does anyone know exactly how these are supposed to be wired? Is only one plug supposed to be grounded, or is there a trick to stacking the washers on the top of the plug, to ground them that way?

Do the glow plugs have to be matched in impedance? It's almost as though all three of the plugs I have (I've got one spare now) have different impedances, so they each glow at a different rate. Does anyone know what the voltages are supposed to be at different points in this system... like before and after the big coil resistor? Am I making a mistake by wiring the grounds of these plugs in parallel? Any suggestions are welcome!!

Thanks,
-Norm.





 

StorminN

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Aug 31, 2010
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OK, after staring at the parts diagram one more time, something just occurred to me... (a light bulb went off!)... are these glowplugs supposed to be wired in series? Like, the hot feed comes in the top of one plug, out the bottom of that one, jumps over the the bottom of the 2nd plug, and then the ground attaches to the top of that plug? (I guess the top & bottoms could be swapped, they're all insulated...) here's a diagram, if anyone knows if this is correct, please let me know... I think I'm going to go home and try this...

Thanks!
-Norm.

 

L4740

Member
Nov 23, 2009
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3rd Rock From The Sun
I believe they are wired in series. So one gets hot, then the other gets hot, then the light on the dash should come on. On the old glow plugs this can take several seconds. Sometimes almost a minute. The newer tractors have the real quick glow plugs but not these older tractors. But, I have never had mine out of the tractor so maybe Vic or someone else with a little more experience can chime in here to confirm this.
 
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StorminN

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Aug 31, 2010
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Hi L4740,

Yes, it turns out, they are wired in series... they are unlike any other diesel I've ever worked on. The glow plugs don't ground through the body of the plug, either.

I went home last night and wired them just like the last diagram above, and.... they didn't work... nothing worked, not even the indicator. "Hmmm..." I thought, "if they're wired in series and some component is not the right impedance, or is blown (open) or something, then nothing will work."...

So I took one of the glowplugs out... an old one, from the cylinder that had not been firing at the start of all of this... and I put two leads on it and touched it to the battery, to see if it would glow... it glowed like right now, and before I could say "poof" (less than a second?), it blew, and spit molten glow plug pieces on the dash of my tractor. Hmm... "there goes $48", I thought...

Then it occurred to me that maybe this plug was bad enough to not work when wired up in the system (after that big coil resistor), but good enough to blow when I put a full 12V to it... so I hesitantly and gingerly put the brand-new glowplug I just got in its place in the system... then turned the switch, and voila, both glow plugs glowed!!

So... then I screwed the glowplugs into the head, wired them back up, turned the switch, counted to thirty, then flipped the switch to start, and the engine kicked over within about two revolutions!! Woohoo! It was about 11pm last night when I tried this, so I didn't try to get the tractor actually running, I just got it to kick over and called it good.

This morning, I went out and the temp was 38F. I did the same thing – held the glowplug switch for about 30 seconds, then cranked the engine, and it kicked over and tried to run slowly, but died. I tried a couple of other times, with the throttle set a little over idle... maybe 1200 rpm? The engine kept trying to start, but died each time. Then, I tried with the throttle set up higher... maybe 2,000 rpm? This time, it started and ran, but ran rough for a few minutes... it was belching white smoke the whole time. I can't tell if it's one cylinder that's not firing completely, or what. After a few minutes of warming up, the white smoke died down, and the engine smoothed out a bit.

I'm wondering if I've got lower compression on one cylinder vs. the other, or if this rough running / white smoke is normal on startup on these old machines? If it was an injector misfiring, would that make black smoke, or white smoke? Not sure if I should start a new thread for this part... but does anyone know the compression test procedure for these engines? I assume the test is done with the engine warmed up?

How about the glow plugs... is it possible to burn them out by leaving them on too long? I've seen people say anywhere from 30-60 seconds of glow time. Most of my diesel experience is with GMC's, and the older GMC glow plugs would self-destruct after about 12 seconds... so I'm a little gun-shy to hold the glow plug switch for 60 seconds on my tractor... it's unnatural to me, but if it will work and it won't kill the glow plugs, I'll do it... but at $48 each for these plugs, I want to hear someone else say "oh yeah, 60 seconds is fine, I do it all the time..."

Thanks for the help everyone!
-Norm.
 

L4740

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Nov 23, 2009
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3rd Rock From The Sun
Norm, it is my understanding that on the newer quick heat glow plugs found on newer equipment you can damage the gow plugs if held "on" too long. With the older tractors I think you would have to hold them "on" for a long long time. To start my L210, I give it a little throttle then hold the key on until the glow plug indicator on the dash glows cherry red. Then hit the starter. It usually will pop right off. If I get impatient and try starting it before the indicator is red hot, that is when I get the white smoke puffing out of the exhaust and have trouble getting it started. I am assuming the white smoke is unburned fuel since the cylindar aren't hot enough yet to get a nice complete burn.
 

StorminN

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Aug 31, 2010
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Hi L4740,

Thanks for the reply. I tried this again a couple of times this weekend...

With the engine cold, and the ambient temperature about 40F, I held the glow plugs on for sometimes as little as 30 seconds, and sometimes as long as 60 seconds, then I hit the starter – and each time, the tractor started hesitantly... it seems like it starts better with more throttle. I even tried the trick of turning the glow plugs back on once the engine was starting to fire... I didn't see a big difference in performance. The amount of glow time doesn't seem to make a difference, either... at least between 30 and 60 seconds. The glow plug indicator on the dash glows after about 10 seconds. I'll have to try just glowing for 10 or 15 seconds and see if it acts the same.

Once the tractor starts, it belches white smoke for a while afterwards... maybe three to five minutes? I'll have to time it. Then it quiets down a bit and smooths out a little. I'll take a video and post a link here, maybe there's something I'm missing...

Thanks for all your help,
-Norm.
 

fj40dave

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B2650, LA534, BH77, TPD35, RCF2060, BB1566, RGA1258
Sep 24, 2009
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Yelm, WA
Stormin....where are you at in WA?

I just rebuilt a L295DT....learned a lot.

The glow plugs took >60sec to get warmed up - turned out to be a bad connection at the battery (almost completly corroded/broke).!

I'm in Allyn.....over between Bremerton/Shelton.

(the white smoke sounds like an over-fueling problem: Diesel Fuel Injector Service in Portland OR can rebuild the injectors and they do an AWESOME job! VERY reasonable!)
 
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StorminN

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Hi fj40dave,

I'm up on the Peninsula, in the foothills outside Sequim... maybe an hour and a half away from you? Good to know about the glow plugs... did they still take over 60 seconds once you fixed the bad connection?

I will take a look at what it takes to remove the injectors and send them down to Portland... thanks for the tip! These days, it's a matter of time and daylight for me... been working ~70 hours a week and not a whole lot of daylight in the time I have off... need a better shop to work in!

Thanks, and good to see another western Washingtonian on here!

-Norm.
 

fj40dave

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B2650, LA534, BH77, TPD35, RCF2060, BB1566, RGA1258
Sep 24, 2009
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Yelm, WA
Hi Norm,

The glow plugs get red-hot in <15 seconds now....very quick, and effective!


Here's a link to DFIS.
I took the tour of their shop when I went down to Portland for the annual VW TDI gathering (TDIFest 2010). I mentioned the difficulties I was having with the Kubota, and they wanted to check the injectors for me. They will do this for free....and if anything is wrong, they can fix 'em. mThere was a lot wrong with the 295's injectors (rebuild all three for $135!!!) The tractor runs really well now! Ask for Mark....tell him "the guy from TDI Fest with the Kubota injectors" sent ya....he'll remember me.
http://www.dfispdx.com/

I really enjoyed working on the 295.....most of the time :D
 

StorminN

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Aug 31, 2010
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Hi fj40dave,

Thanks for the $0.02... however, on these glow plugs, I don't think that would work. They don't ground through the body of the plug, so they need some wire to ground...



So, I think the glowplugs are supposed to be wired this way... the hot feed from the dump coil is coming in on the right, and the ground is going off to the left... the blue wire jumping from one glow plug to the other is a solid aluminum wire that I assume is original Kubota equipment, because it's painted the same blue as the engine...



... at least that's what the Kubota diagram shows, and I've tested this, and it does make both of them glow... the problem I'm having now, however... is that even with both plugs glowing, when it's 19F out like it is right now, the old L200 still doesn't want to start! So today I bought a magnetic block heater, we'll see if that helps...

-Norm.
 
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fj40dave

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B2650, LA534, BH77, TPD35, RCF2060, BB1566, RGA1258
Sep 24, 2009
417
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Yelm, WA
Cool....sounds like ya got the glow-plug wiring figured out. :)

In this temperature, is your fuel slightly gelled causing a no-start situation?
 

SpudHauler

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RTV 1100 CW-A
Sep 8, 2010
97
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Canada
More a maintenance issue, but you could check your valve clearances to make sure you are getting full compression. One tight valve can make a huge difference and it's not hard to check, even if you just record all the clearances and compare them to each other to see what they are currently set at.
Don't know if a de-compression lever is used on this model, but also a source of trouble if it is sticky and holding valves open.
Good compression, good fuel, two biggies for ease of starting.
Quick fuel test is to setup a little tank and line and gravity feed fresh new fuel as a test.
 

StorminN

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Aug 31, 2010
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Hi guys,

All good questions... I'm not sure if the fuel is slightly gelled or clouded, I will check. I was able to start the tractor the other morning at 17F by using a magnetic block heater (left on overnight), and then a heat gun to heat the head and injection lines, fuel filter, intake manifold, etc. The engine didn't start with the heat of the block heater alone, but after 10 minutes or so of heating other parts with the heat gun, and then cranking it over, it started reluctantly. Once it was started and warmed up, it ran well all day, and I plowed the snow off of 3,500 feet of driveway... the old Kubota earned its keep! I will check the fuel, it's now right around 32F, so we're through the cold spell for now...

I will check the valve clearance, too... I think my owner's manual shows how to check that. This model has the Z1100 engine, which does have a decompression lever. The cable for it is sticky, but I think the lever is completely released...

Thanks guys, for the help...

-Norm.
 

StorminN

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Well, I haven't had much time to get out there and try to use the old L200, but I was hoping to use it today – so last night I plugged in the 200W magnetic block heater I bought for it.

Today around noon, (after about 14 hours of the block heater being on) I tried to start the tractor... it was about 32F out. I checked the fuel in the tank, and it looked fine... no clouding or gelling. I turned the glow plugs on, and once the indicator was glowing bright I counted to 30, then tried cranking it... here's what happened...

http://www.youtube.com/watch?v=4mHTmfjtXmM

I'm not sure what's happening here... it sounds like it runs ok for the first second or two, but then it starts missing and doesn't want to run. In fact, if I don't switch the glow plugs back on, it won't continue running, it will die. You'll notice it's a mixture of white and black smoke, mostly white... (not firing, not firing, not firing, then firing with too much fuel, repeat)... one thing to note... the rear cylinder is the one that's not firing. After this video, I felt the exhaust manifold and the front cylinder exhaust was warm to the touch, but the rear cylinder exhaust was still mostly cold...

After this video, I grabbed my heat gun and heated up the fuel filter, injection lines, and injectors for a few minutes... until they were more than warm to the touch... then I tried starting the tractor again, and it did the same thing as in this video... didn't want to run, and it would die if I didn't leave the glow plugs on.

What I forgot to try today was to heat the intake manifold and air cleaner with the heat gun, and then when starting the tractor, point the heat gun so warm air is going directly into the air intake... that's how I got the tractor started last time, when it was 17F out.

I did confirm that the decompression lever is completely retracted... no idea what it looks like on the inside of the engine, but on the outside, the cable is loose and the lever is up against its stop.


Thanks,
-Norm.
 
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fj40dave

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B2650, LA534, BH77, TPD35, RCF2060, BB1566, RGA1258
Sep 24, 2009
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254
63
Yelm, WA
Ugh....that's painful to listen too! :(

I think I would start with pulling the injectors....check to see if that rear one is stuck or gummed up.
 

StorminN

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Aug 31, 2010
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Well, I finally had time to work on the tractor this morning.

I started by adjusting the valves. All four were tight... no slop at all. I dialed in a tight 0.010" clearance on all four... the owner's manual says 0.008" to 0.010" clearance...



I put the valve cover back on, ensured that the decompression lever was not engaged (you can view it through the oil fill) and then tried to start the engine. It was 37F out, and I hadn't used a block heater at all. I glowed it, cranked it over and it fired right away, then died. I glowed it again, cranked it again, and it fired again, and this time I held the glow plugs on to keep it running... no use describing it, when there's a video... sorry for the poor quality...
http://www.youtube.com/watch?v=nJ8sM-6ysIU

So I'd say this engine still has a compression / injection problem. I'm guessing it's compression, and it's running at first because the cylinder is hot from the glow plug – but then as soon as cold air starts going in there, it starts wanting to quit. I also say this, because if I put a heat gun on the intake... like direct it right into the intake, this motor will start and run... so I'm not convinced it's entirely a fuel / injection problem... but I'm not saying the injectors are perfect, they could probably use a tune-up!

I don't have a compression tester, but I do have a guy that offered to pop-test the injectors for me... so after I took this video, I removed the injectors.

I was surprised how loose the nuts were on the studs that hold the injectors in – and even more surprised that the nuts are brass. Actually, three of them are brass... they look like 8mm x 1.25mm nuts that take a 14mm wrench... then one was a steel nut, it took a 13mm wrench. I'm guessing someone lost an original nut at one time and replaced it. But yeah – none of them were super tight. Made me think possibly? a little compression was leaking by this way on the rear cylinder? The seal looks ok, so who knows...

The rear injector had a different soot pattern on it (it's the one on the right in the pic).



Hopefully my friend with the pop tester will be available tomorrow... we'll see...

Next up are the fan bearings... think it needs new ones?



-Norm.
 

WarrenKubotaL210

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Equipment
L210
Jan 9, 2012
1
0
0
Gulfport, MS. USA
StorminN, I have a Kubota L210 and I have been having problems starting for a very long time. I tried everything thinking the compression was low or maybe the injectors were worn. However it never occured to me that the glow plugs needed to be wired in series. They were wired in parallel and until I read your thread, I did not know they were suppose to be wired in series. I immediately went and corrected the connections. Then I let it glow until the dash coil glowed red and it cranked right up. I have a new tractor! Thanks for your help. WarrenKubotaL210
 

davej42

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Equipment
l200
Dec 20, 2014
3
0
0
sheridan, ar
I purchased a l200 last summer and it would not start. We found a bad glow plug and thankfully the wiring was dried up. I didn't try to start it or turn the switch on, so i traced it back. I found a splice and i am assuming that is were the resister pack goes but it doesn't have one. Also the controller coil on the dash is burned out and has been bypassed. So i need those 2 parts. I don't have part numbers for those can anyone give me the part numbers or suggest were to find them? Or the value of the resister in the circuit? It sits on the right side of the tracker just below the gas tank