Injector pump trouble

DennisStahley · Feb 16, 2007

Hi All
Well its been a little over a year since I have posted a question on my tractor as I have been sick and unable to work on it but have tried the last couple days to do so but since I have become disabled some days arent good to me but trying to get back in the groove. Here is my problem, I bought a Kubota L245DT and wont run? I have cleaned fuel tank out ,new glow plugs, but still no go, but here is what I have found it seems like there is no fuel getting to the injectors as I took off the pipe to them and nothing comming out?(see why i think it is not getting fuel)haha so I took off the pipes that come off the injector pump the 3 pipes and nothing is comming from the pump? should there be fuel comming out of these pipes? the shop manual says it is under high pressure but there is none here. Also(dumb question) but where does the spark come from to fire the fuel? is it from the glow plugs? As you can see I don't know much about diesel engines and now while on social security disability there isnt a whole bunch of money to take to mechanic so hoping you guys can help me out. I know it's a old tractor and when I bought it for $2,300.00 I thought it was a good deal, it did not run but for a few seconds when I bought it, as it was setting up for 2 years and diesel was bad so I cleaned out tank then I got sick so it sat another year untill now and I am ready to get it going if I can. it only has 789 hours on it if that is right. I can get it to turn over fine but no starting. If anyone can give me any ideas that would be great you can E-mail me at BigD924@aol.com if that is possible and I will check here also to see if anyone can think of anything that might help me.
Thanks in advance
Dennis Stahley
Bradenton Fl.

KJM · Feb 17, 2007

I'm sure some more "local" people will chip in with advice, but here goes:

Diesels need fuel and air. There is no spark

- it ignites by simply compressing the air in the cylinder and then injecting a whiff of diesel at the right moment. So no messing about with spark plugs! The glow plugs just glow red hot so that when everything is cold, the atomised diesel is sure to go bang.

If you aren't getting fuel from the injector lines:

(1) Check the filter.
(2) Bleed air from the filter housing. There is a screw/bolt/something that lets the air out. Open it till you get bubble free diesel making a mess everywhere.
(3) Bleed the injector pump. There is another screw/bolt/thing on the injector pump for the same purpose. If gravity works to get the fuel coming out, that's fine. If not - pull the manual decompression lever and crank.

Once you have (3) done, you now have an air free fuel supply. The tiniest air leak on the suction side will render your engine insensible!

Keep clear of the high pressure lines! These things are around 2000psi on my little B7100 - enough to inject diesel under your skin. "Cracking" injectors (loosening the feed from the top of the injector to see if fuel "squirts") is dangerous - use a bit of paper draped over the top of the injector and then crank it over. Look for diesel on the paper! Safe!

The injector pump has a little pump (called a "lift" pump) that actually sucks the fuel from the filter - this might be blocked or not-functioning. This can be fixed by mere mortals, but if the injector pump (high pressure side) is not working this normally needs an "expert".

Hope this helps a bit!

DennisStahley · Feb 17, 2007

Well thank's for the info. I have done the bleeding of the fuel filter and the injector pump to no avail yet. Maybe the lift pump is clogged like you said I will try that and see if I can find out anything. I know when I try and crank it there are 2 gaskets one on top where throttle lever goes in and one on side of pump that while cranking fuel seeps out these gaskets. I guess I should replace these gaskets first and see if that helps. On this injector pump I am guessing it is the whole thing on the side of engine? Quite large thats for sure but thanks for the response.

Dennis

KJM · Feb 17, 2007

Yes - it is quite large! On the back of mine lurks the hydraulic pump for the tractor hydraulics. Don't know if the one on the L series is the same..

The only L series I've tinkered with was a fair bit different from my B series (there is MUCH more space!) - it was an L260 I think and had a seperate lift pump - the fuel line from the filter went via a T shaped widget which was a pump (as we discovered - the owner has now purchased a shop manual to avoid these embarassing discoveries mid-job). His pump had a filter screen which was plugged.

On mine - the fuel line goes into the body of the injector pump and there is a small circular disk which covers the lift pump.

Good luck!

DennisStahley · Feb 17, 2007

Yes it is quite big isnt it. On mine the fuel tank goes to the filter then to the injector pump, I haven't checked to see if there is a screen in the pump yet,I don't know where for sure the screen would be, I do have the shop manual for it but it does not show that i don't think.I want to say thank you for replying to me as no one else has replied to my question,must be to old of a tractor for anyone to comment on?

Dennis

KJM · Feb 18, 2007

DennisStahley said:
...I want to say thank you for replying to me as no one else has replied to my question,must be to old of a tractor for anyone to comment on?

Dennis

My impression is that most people have new shiny tractors

- mine is an early 80's B7100 with 3700 hours on it. So the engine is approaching run-in!

Diesels are pretty easy to diagnose fault wise, in my limited experience. Once you have diesel coming out of the injectors - there isn't much else that could be wrong! The injector pump on my B7100 is pretty simple - I reckon I could repair it if needed. There isn't very much to it - the only tricky bit is timing! The bigger/newer Kubotas have more complex pumps - but when all is said and done, pumps is pumps.

Your symptom of a year back - running for a bit and then dying sounds horribly like fuel feed issues to the pump. I have a diesel powered vehicle that had the same kind of problem. Turned out the lift pump was dead - I got it to the diesel mechanic by putting an electric fuel pump in series... If you had an electric fuel pump handy it'd be a simple way to ensure fuel at the injector pump (modulo stuck one way valves, bits of grot etc). Just a thought!

Best of luck!

workinallthetime · Feb 19, 2007

i think this may have allready been said but here goes;
no fuel to injectors then check fuel supply to pump as well as return line from pump. Diesel engines have fuel return lines at the injecotors and at the pump. should a return line become blocked off this will cause a kind of vapor lock and prevent the engine from running so pull off the return line at the pump and crank. fuel? no fuel? no fuel means no supply. like it was said get a 12 volt fuel pump say off a 98 chev 6.5 and run fuel to the pump and see what happens when you crank it, if you get fuel out of your return then you know the fuel injection pump is moving if its not you may have mechanical problems. injection pumps are driven off gears that are driven off the engine. if you get fuel then start your bleeding proceedure. install all fuel lines from pump to injectors but dont tighten the injector lines in fact dont even thread them. start cranking the engine until you get fuel out of the shortest line then tighten it and go down the line until you have gotten fuel from all of them. if it starts while your bleeding shut it off you will inject more air.
hope that helps