newly purchased L285 won't start

[rickrmf]

Hi,
I just bought an old Kubota L285 form a local craigslist.
It was not start, so he took it to the local dealer, and they said it had low compression. He managed to start it once using a little ether. Ugh.
The former owner and I were guessing that possibly the rings were stuck from setting.
I did the mystery oil dosing that I had seen on the forums. I shot a little diesel in the glow plug holes, and I was able to get it to fire off and run for about 30 seconds. It smoked from the leftover mystery oil, but it was encouraging.
Then I pulled the injectors out cleaned them and looked them over.
There was a little junk in them but not as much as I expected.
Right now I have them hooked up to the pressure lines, hang out from the motor.
Sometimes the have a pretty good spray, but I don't know how much it should be, as I'm new to diesels.
I'm pretty sure at this point that the lift pump may be weak.
Will that have an effect on the volume and spray pattern.
I don't think the old tractor is in as bad a shape as it was originally diagnosed.

What kind of tips or advise can you all give me?

Thanks rickrmf

 

[D2Cat]

Rick, you can go to Harbor Freight an pick up a compression testing kit for about $30. There is a fitting in the kit that goes into the plow plug hole. I'd suggest know what the compression is and then you know which direction to go. Make sure the valves are adjusted properly to get an accurate reading.

Spraying ether in there can make a quick journey to the promised land. It's a REAL good way to increase you rebuilding cost! The ether only confirms you have additional problems yet discovered.

Welcome to the forum, and post some pictures of your project.

 

[Dave_eng]

When an engine is difficult to start the Glow plugs should at least be evaluated as a possible culprit.

On some models the Glow Plug indicator will glow even with non working GP's

Since you have removed the glow plugs, plse post a picture of one.

The wiring diagram I found says that the L285 has parallel wiring for the GP's but there are other models in that series of L's which have series wired GP's

Do you have a multimeter and if so check the resistance of each glow plug terminal to it's body or threaded portion with all wires disconnected from it.

You should read around 1 ohm if my memory is OK.

Don't go applying battery voltage to the GP's. The resistance test is all you need for now.

Dave

 

[JerryMT]

Hi,
I just bought an old Kubota L285 form a local craigslist.
It was not start, so he took it to the local dealer, and they said it had low compression. He managed to start it once using a little ether. Ugh.
The former owner and I were guessing that possibly the rings were stuck from setting.
I did the mystery oil dosing that I had seen on the forums. I shot a little diesel in the glow plug holes, and I was able to get it to fire off and run for about 30 seconds. It smoked from the leftover mystery oil, but it was encouraging.
Then I pulled the injectors out cleaned them and looked them over.
There was a little junk in them but not as much as I expected.
Right now I have them hooked up to the pressure lines, hang out from the motor.
Sometimes the have a pretty good spray, but I don't know how much it should be, as I'm new to diesels.
I'm pretty sure at this point that the lift pump may be weak.
Will that have an effect on the volume and spray pattern.
I don't think the old tractor is in as bad a shape as it was originally diagnosed.

What kind of tips or advise can you all give me?

Thanks rickrmf

Before you start taking things apart, there are a few simple things you can do when you have a no start situation. First I assume that the engine is in reasonable mechanical condition, i.e. good compression.

Make sure that you have adequate fuel flow to the injectors. Start at the tank and make sure that there is a good flow of fuel at tank outlet. follow that to the fuel filter and make sure that you have a gush of fuel at the discharge side of the filter. It goes without saying that if you just have fuel dribbling from the tank or from the filter, then you need to eliminate the blockage. If you have a lift pump, disconnect the discharge line and make sure that it is pumping fuel again, not dribbling. Some lift pumps have a cleanable screen in them.
Open the bleeder on the injection pump and make sure that you have fuel there when you crank.

Once you have established that you have good fuel flow then check the glow plugs. A simple resistance check should tell you if they are good and then make sure they are getting juice when you try to start.

Check the air induction system (air filter and manifold) for blockage

Stay away from starting fluid. You can damage the piston crown and the rings and lands if you are not careful.

If the engine is in reasonable mechanical condition and it has an adequate supply of fuel, the glow plugs are functioning properly and the battery can crank it over briskly, it should start.

 

[North Idaho Wolfman]

He managed to start it once using a little ether.

That is a BIG NO NO with kubota engines!
NEVER use ether, no matter what!

#1 get a compression tester and test the cylinder compression, that would be the #1 starting place!

 

[rickrmf]

Thanks for your interest and the reply. There is not much coming out of the lift pump.
At one point I had pretty good spray at the injectors, but I think the lift pump does not keep up with the injection pump.
I got a small electric fuel pump from a guy down the street, and I'm going to see if that helps any.
When I first got this tractor and it was little warmer outside, I put a little diesel in the glow plug holes, pre-heated, and it fired off for about 30 seconds or so.
That's when I started in looking at a possible fuel delivery problem.
I got the tank cleaned out and replaced all the rubber lines.
Since it fired off once, I think if I keep at it and get it started, then let it run for good amount of time, it might start working better.
Oh yeah, I was told that the compression was about 300PSI across all the cylinders.
That's not real good I'm told, but some od timers say it's enough.

 

[rickrmf]

Oh, I just remembered. How much spray should I see from the injectors?
6-8 inches maybe?

 

[prof.fate]

300 seems to be below spec...if it runs it won't have much power.

http://www.engineprofessional.com/TB/TB030915-1.pdf

 

[North Idaho Wolfman]

300PSI is on the low side but it should start and run.

Bypass everything and feed fuel directly to the injection pump from a bottle above the pump.

The lift pumps on these models move very little fuel as that's all it needs to run.
I will caution you on using an electric pump as most are high pressure and could damage the seals on the injection pump.
Being that the fuel tank is above the injection pump, 99.9% of the time the lift pump is not required for it to run properly.

Distance is not the key, it's spray pattern evenness with no drips.

 

[007kubotaguy]

Hello
As others have said it will run with 300psi. When using the electric fuel pump don’t bypass the fuel filter.
Good luck Lance

 

[JerryMT]

Oh, I just remembered. How much spray should I see from the injectors?
6-8 inches maybe?

Since you cleaned the tank outlet, what did you find? Did you change out the fuel filter? I doubt compression is your problem since you get it to start after putting fuel in the cylinders manually.

Your observation that you have low flow at the lift pump discharge is indicative of an up stream blockage or a defective lift pump. if you put a "T" with a pressure gauge at the lift pump discharge, you should see 2-4 psig at the lift pump discharge IF the upstream line is not blocked. Lift pumps are there for a reason and it must be necessary. As Wolfman says, it should be able to run that way (Our Ford 4610 does!) but Kubota didn't design the fuel delivery system to run that way for some reason AND THUS THE LIFT PUMP IS REQUIRED. My guess would be that the fuel tank height above the injector pump is such that with the nose pitched up, there is not enough static head from a partially filled fuel tank to supply the flow rates required for full power, but that's conjecture on my part.

 

[rickrmf]

Well,
Here's an update.
Finally back on the Kubota, due to better weather and time available.
After reading the posts from here and talking to local shops I decided to look in to removing the injection pump to check it out or maybe send it in for a rebuild. a guy told me to see if the fuel rack was moving.
I found the fuel rack was not moving. I got it inside on the bench, and with a lot of spray cleaner and some careful tapping it now slides freely.
The plungers all seem to have a good stroke and snappy return.
I'm going to clean it up some more along with some other parts and put it back together and see if it makes a difference. Before it would only spurt up about 3/4" or so.

I'll try to update things, and maybe have some more questions.
Rickrmf

 

[D2Cat]

Rick, it's good you discovered the fuel rack not moving and freed it up. You could have discovered that by removing the side place on the IP while it was still in place. It'll probably fire right up and run fine.