Grand L3130 smokes heavily at startup and runs rough at high rpm

[Grand L3130 Guy]

Hi guys, first post, thought I’d jump right in with a some engine issues that have me scratching my head.

I have recently purchased a 2003 L3130 with ~780 hrs. Have spent some time going over the tractor taking care of some "differed" maintenance items. One thing that’s really bugging me is that it smokes HEAVILY and miss fires some at startup. It’ll miss for approx ~10-30 sec and smoke heavily for ~60 – 90 sec, really a pain inside my shop. It will eventually clear out and run smooth.

After trying the fresh fuel, new fuel filter, new air filters, and Diesel Kleen thing with no remedy, I decided to pull the injectors.

One of the injectors appeared to be a leaker (wet tip) and another had a nice carbon stalagmite forming on the tip, the third looked brand new, possibly a replacement by the PO. No problem, some time in the sonic bath and a little TLC and the injectors were in good shape. Thought for sure this was “it”.

While I was in there I adjusted the valves too. 4 out of 6 were out (3 exhaust, 1 intake), set them with 0.007” GO and 0.008” NO GO and slapped it back together. It cranked up smoking and missing just like I hadn’t touched it. When I cranked it, I hadn’t reinstalled the exhaust manifold/muffler yet (VERY loud) and noticed that it only smoked/missed from the forward most cylinder. Thinking I had botched one of the injectors, I pulled the front one, went back in to it, cleaned it again. But this time when I reinstalled it I swapped it with the one in the middle cylinder.

Cranked it back up, still smoking and missing just like before from the front cylinder only. It still settles down and runs smooth after about a minute or so.

In addition, I’ve discovered another symptom. Once warmed up/settled it runs smooth and smoke free from idle ~700 rpm up to ~2200 rpm, at 2300, the front cylinder starts to miss/smoke and it gets worse and worse as you go up full throttle (~2700). The smoke is light colored and has a heavy smell of unburned diesel.

One other thing I did while I was in there was to pull and test each glow plug. No issues there, they all checked out fine but I had a hell of time removing the one in the front cylinder. After unthreading it, it was still stuck in the hole by carbon buildup, probably not a coincidence.

So at this point I’m thinking I should pull the head and see what I find or could this be the injection pump? This next round of investigation may be a bit expensive.

What do you guys think? Any ideas/insight would be greatly appreciated.

Thanks in advance and Merry Christmas!!

 

[eserv]

Hi guys, first post, thought I’d jump right in with a some engine issues that have me scratching my head.

I have recently purchased a 2003 L3130 with ~780 hrs. Have spent some time going over the tractor taking care of some "differed" maintenance items. One thing that’s really bugging me is that it smokes HEAVILY and miss fires some at startup. It’ll miss for approx ~10-30 sec and smoke heavily for ~60 – 90 sec, really a pain inside my shop. It will eventually clear out and run smooth.

After trying the fresh fuel, new fuel filter, new air filters, and Diesel Kleen thing with no remedy, I decided to pull the injectors.

One of the injectors appeared to be a leaker (wet tip) and another had a nice carbon stalagmite forming on the tip, the third looked brand new, possibly a replacement by the PO. No problem, some time in the sonic bath and a little TLC and the injectors were in good shape. Thought for sure this was “it”.

While I was in there I adjusted the valves too. 4 out of 6 were out (3 exhaust, 1 intake), set them with 0.007” GO and 0.008” NO GO and slapped it back together. It cranked up smoking and missing just like I hadn’t touched it. When I cranked it, I hadn’t reinstalled the exhaust manifold/muffler yet (VERY loud) and noticed that it only smoked/missed from the forward most cylinder. Thinking I had botched one of the injectors, I pulled the front one, went back in to it, cleaned it again. But this time when I reinstalled it I swapped it with the one in the middle cylinder.

Cranked it back up, still smoking and missing just like before from the front cylinder only. It still settles down and runs smooth after about a minute or so.

In addition, I’ve discovered another symptom. Once warmed up/settled it runs smooth and smoke free from idle ~700 rpm up to ~2200 rpm, at 2300, the front cylinder starts to miss/smoke and it gets worse and worse as you go up full throttle (~2700). The smoke is light colored and has a heavy smell of unburned diesel.

One other thing I did while I was in there was to pull and test each glow plug. No issues there, they all checked out fine but I had a hell of time removing the one in the front cylinder. After unthreading it, it was still stuck in the hole by carbon buildup, probably not a coincidence.

So at this point I’m thinking I should pull the head and see what I find or could this be the injection pump? This next round of investigation may be a bit expensive.

What do you guys think? Any ideas/insight would be greatly appreciated.

Thanks in advance and Merry Christmas!!

Hi!
Sounds like late injection timing, Do a compression test to verify that all the cylinders have good compression then check the injection timing. Usually removing one shim will correct it sufficiently to clear up the smoke. This isn't a common problem on L tractors like it is on B's but I have adjusted a few!
Ed

 

[Grand L3130 Guy]

Thanks Ed!!

Is the flywheel 1TC viewing window accessible without splitting the enigine from the tranny? When doing the valves, I couldnt find it so I used a dial indicator to find TDC. Guess I could calculate the piston travel distance at 17 to 19 BTDC but using the window sure would be easier.

Thanks Again!!

Chris

 

[eserv]

Thanks Ed!!

Is the flywheel 1TC viewing window accessible without splitting the enigine from the tranny? When doing the valves, I couldnt find it so I used a dial indicator to find TDC. Guess I could calculate the piston travel distance at 17 to 19 BTDC but using the window sure would be easier.

Thanks Again!!

Chris

Yes it is, on the right side of the engine. Closer to 19 BTDC is better. I maybe shouldn't admit this but if I have an engine running like yours is I don't even bother to check what the timing is! I just remove the thinest shim in there and the problem is fixed.Some engines seem to need a little more advance than others. It's kinda like adjusting timing "by ear" on a gasoline engine.

 

[Grand L3130 Guy]

Well, quick update on my progress. Checked compression, bad news on the front cyclinder Number 1 & 2 checked out at about 575 psi each, but #3 came in at only 400 psi

For those out there reading along, Harbor Freight has a reasonably priced diesel compression test set (Part #93644) that has the correct adapter (glowplug = M10 X1.25) for a L3130 engine. Only lists for $29.99, but keep in mind a lot of their stuff is "disposable".

So the now the next question, is it the valve train or the cylinder/rings.

Going to pull the head off and see what I find, will keep you posted.

After I all this I do also plan to check the injection timing before I button it back up just to be sure.

Thanks!!

Chris

 

[whitetiger]

Hi!
Sounds like late injection timing, Do a compression test to verify that all the cylinders have good compression then check the injection timing. Usually removing one shim will correct it sufficiently to clear up the smoke. This isn't a common problem on L tractors like it is on B's but I have adjusted a few!
Ed

Your thinking the timing is off on one cyclinder????
Just remove a shim from under the pump will correct the problem?????
Are you serious????????????????????????????????

 

[kuboman]

You may have weak delivery valves on the IP. The lower compression on one lung was likely caused by a bad injector.

 

[birddogger]

is it the valve train or the cylinder/rings.

I would certainly check the valve lash. A real loose lifter could do it. If one or the other was running too tight it could also be starting to cut a valve seat.
I would do a wet compression test on all cylinders before looking toward the rings.

 

[Grand L3130 Guy]

Update – got the head off, the valves don’t look too bad, not great by any stretch, but I guess diesel a head is only going to look so good (this is my 1st), they should clean up well with a little lapping or light surfacing work. #3 was in slightly worse condition than 1 & 2, plus it had the smallest sealing band on the valves. Going to let the machine shop take care of it because it really needs a good hot tanking. Should be done by Fri. No real “ah ha” conditions found in the head but you never really know b/c proper valve sealing is a delicate issue.

What I did find to be a bit unusual was the Intake rocker on #3. It had 0.019” of play up/down the rocker shaft (ie I could insert a 0.019” feeler between the rocker and the washer). With the rocker assembly removed, the weight of the heavy side of the rocker is enough to cause it to freely turn about the shaft. The rocker bore and rocker shaft mic’d in good. #3 Intake is the farthest forward rocker, the other 5 are held under mild but noticeable tension by springs on the rocker shaft. #3 intake just has an end nut, lock washer, washer and thrust washer. The thrust washer appears to be too thin to me. I’ve ordered some shim stock from McMaster Carr and plan to shim #3 intake to similar tension as the others upon reassembly. I can see this possibly causing valve open/close inconsistencies at high rpms. Not sure it would explain the startup issues though. I didn’t find this until after I pulled the head and removed all the valves. Wish I had found it first, I would like to have tried to resolve it first to see if it really was contributing, oh well, a nice fresh head isn’t a bad thing, only time and $$$.

The bores look really good, no sign of blow-by, so I’m not going in to the bottom end to pull the piston. I will run a cold compression check for comparison after I get it all put back together and if #3 is still way off I may go back in and pull the piston.

Anybody have the torque spec for the rocker shaft end bolts, can’t seem to find it in the WSM.

That’s it for now, will update again after I get it back together.

Cheers!!

 

[eserv]

Hmmm, I can't see how the rocker issue could cause the starting, smoking issue you described. Check that all the pistons come up to the same height ( called piston protrusion on a diesel because they come above deck height). I have a hunch that # 1 may be lower than the rest. If it is you probably have a bent connecting rod. Lower piston causes lower compression ratio and causes lower compression pressure, this would definitely cause the symptoms you describe !( You can easily bend the rods in a Kubota with either!)
Ed

 

[eserv]

Your thinking the timing is off on one cyclinder????
Just remove a shim from under the pump will correct the problem?????
Are you serious????????????????????????????????

No, I didn't think the timing was off on one cylinder, I thought it might be off on ALL cylinders though. I advised to check compression first to eliminate that and He found that low so the timing idea is not the issue. But yes, many kubota's, when they run like that, are late in timing and removing one shim will correct it.
Ed

 

[Grand L3130 Guy]

Hmmm, I can't see how the rocker issue could cause the starting, smoking issue you described. Check that all the pistons come up to the same height ( called piston protrusion on a diesel because they come above deck height). I have a hunch that # 1 may be lower than the rest. If it is you probably have a bent connecting rod. Lower piston causes lower compression ratio and causes lower compression pressure, this would definitely cause the symptoms you describe !( You can easily bend the rods in a Kubota with either!)
Ed

Winner winner, chicken dinner….I have a bent rod.

When I checked the pistons like you recommended Ed, 2 had protrusions and one was recessed ~1/8th".

Dropped the oil pan, pulled off the rod cap and popped out the rod/piston. The rod look like a Chiquita banana.

The piston/rings look good, going to mic all ring gaps tomorrow and give them a dip in the sonic bath. The wrist pin is still straight, looks like all I need is a new rod assembly, circlips and a new oil pan gasket.

Finally a definitive root cause…

Thanks to all that helped me figure this out!!

Chris

 

[10swampdonkey]

I have a L2202DT. Today I was plowing snow, and had to jump a vehicle that needed to be moved for snow removal. I shut off tractor while the dead vehicle was cranked and started to save the alternator from damage.
When I restarted my tractor, it ran rough at lower rpm, and smoked blue a lot. I ran the rpm up and it smoothed out, but still smoked. It did clear when running at 1200+ rpm, but would start smoking blue again if idled down. I plowed for another half hr or so, then top gear and high rpm run a few blocks back to my house. Ran fine and not seeming to be smoking now, but when I came back home I cleared more snow with revs up for maybe 5 min, and then parked.
This is the first time I have seen anything like this since I got the tractor in August. I have around 20 hrs added to the meter since then.
All filters were changed and oil as well. With my little experience, I was thinking dirty/clogged injector? My thinking this was due to the sudden onset after restarting warm and running smooth after.
Should I be trying some sort of injector cleaner additive?
Thanks,
Todd

 

[10swampdonkey]

I didn't get an answer here. Most likely because the original thread was solved. I put it here as it seemed to me to be a similar issue.
I know an older guy in town who has 3 kubota engines in equipment he owns, and he told me he had water in his air intake before, somewhat like carburetor icing on a gas engine. The weather, temp, and humidity were right for that.
I checked my air breather, no moisture. He then told me to add an antigel/dispersant conditioner to tank. I added lucas winter formula, and a bit of diesel kleen. Seems to be running back to normal now. Nice and smooth, with good clear exhaust. I am really glad my problem was more simple than and bent rod.

 

[skeets]

Good on ya swampdonkey ( thats what my fiend in canada calls moose) yeah bad fule can give you fits, glad you got it cleaned up