Problems with Kubota Z400 2-cylinder engine

[Tumphu]

Hi folks!

New in here, good to be with Pro's.

Im asking a bit help with my Kubota Z400 engine. I bought it as "almost scrab". It has stand like 2 years, but the seller told it was in running condition before that, maybe had some valve problems but did run.

Now i've tried to get it running, but havent got it yet...

I've got diesel from pump, injectors and nozzlez cleaned (not tested tho).
Glow plugs are dead, but tried with really careful amount of start spray. It just caughts couple times, but when start gas burns off, its all dead end. Just keeps starting.

Today i got an old pressure test for diesel, going to test it tomorrow if i have time, and soon going to take injectors to diesel workshop. BUT, now I'd need some help with injection pump. Can it be opened and repaired by self?

I think there is going to be something wrong in that pump, because when shutdown is pulled all the way to STOP, Injection pump starts to give fuel. Before that nothing. So someone has opened it for sure and now it needs to be remaked.

Any guides for Diesel Kiki 2-port diesel injection pump reconstruction / maintenance?

Anyt other hints that would help me to get the motor running?

Done so far:
- Adjustet valves
- Cleaned all fuel lines and tank + new filter
- Changed oils
- Cleaned injectors, and took all air of from fuel system
- Noticed that STOP- lever works the opposite and determined its because the injection pump (am i right?)
- Noticed that glow plugs are both dead
- Borrowed pressure tester for cylinder pressure test.

Best regards
Tuomo, Finland

 

[coachgeo]

Glad you were careful with start fluid...... but if it is Ether based (for petrol engines) then don't use it. Esp. since these Kubota's are indirect injection. Glow plugs are very inexpensive so just replace them and eliminate that issue.

Air getting into the system will also not let a diesel start or run such as a pinhole in fuel line or fuel attachment etc.

 

[Tumphu]

Yea I havent used it much, just for small boost while starting because dont want to give 24V to 12V starter for higher start rpm. Im sure it would get burnt.

Are these indirect kubota engines injector spray pattern the same as direct? Or is indirect more dripping?

I installed injectors to fuellines but didnt install them to head. Then put small cup under injectors and turn engine over with start to see the pattern, and it werent spray pattern, more like really small squirt from medical douche.

--
Tuomo

 

[Tumphu]

Today I installed new glowplugs, no help. Didnt start.

Somehow I think there is problems with injector pump. Is there any manual / guide for fixing it?

Thnx for help!

 

[D2Cat]

From your description of your injectors, "Then put small cup under injectors and turn engine over with start to see the pattern, and it werent spray pattern, more like really small squirt from medical douche." I would suggest replacing them, or at least have them tested at a injector/pump shop.

 

[coachgeo]

You might try running fuel cleaner thru injectors. Have engine pull pure injector cleaner out of a bottle instead of mixed in fuel tank. I like Lubro Molly Diesel Purge.

You can also pull the injectors and soak them in a bottle filled with carb cleaner too. 3 glass jars and soak for a few days? Don't know if one can disassemble Kubota injectors but if you can, assume they are like MB injectors I've pulled apart to soak..... YOU CAN'T MIX PARTS between injectors. Unless of course your going to send them to shop re calibrate them anyway. Aluminum pie pans are good for soaking after disassembling the injectors. Use a good carb cleaner... Pans are for keeping the parts organized while soaking disassembled.

Remember diesels can't have ANY air in the fuel lines. Could you be sucking in any air in your temporary engine test stand?

What are you going to use the engine in?

 

[North Idaho Wolfman]

Did you do a pressure test on the cylinders?

 

[Tumphu]

You might try running fuel cleaner thru injectors. Have engine pull pure injector cleaner out of a bottle instead of mixed in fuel tank. I like Lubro Molly Diesel Purge.

You can also pull the injectors and soak them in a bottle filled with carb cleaner too. 3 glass jars and soak for a few days? Don't know if one can disassemble Kubota injectors but if you can, assume they are like MB injectors I've pulled apart to soak..... YOU CAN'T MIX PARTS between injectors. Unless of course your going to send them to shop re calibrate them anyway. Aluminum pie pans are good for soaking after disassembling the injectors. Use a good carb cleaner... Pans are for keeping the parts organized while soaking disassembled.

Remember diesels can't have ANY air in the fuel lines. Could you be sucking in any air in your temporary engine test stand?

What are you going to use the engine in?

I've tried cleaning them, no use. Im going to take them to diesel-shop with injector pump and ask to test and adjust those. Hope it wont cost too much...

Also I've opened injectors and didnt mix parts. Found guide from Youtube how to disassemble them, that was pretty easy.

for North Idaho Wolfman, No I havent done pressure test yet. I have pressure testing meter home, but it doesnt have right size adapter to get it plugged in. Going to need to go to visit friend with lathe so he can mill adapter for me and then I can test the pressures of cylinders.

--
Tuomo