Z482 engine

Craig p

New member
Jan 23, 2015
3
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New Zealand
I have a z482 that has stopped running. It tries to start when you crank it but won't run. I have checked all fuel lines and filters. Have removed head and checked the valves etc these were fine. Have got the injectors reconditioned and she still won't start. Pulled the top of the injector pump out and the cam in there all looks fines and the primary/transfer pump is operating correctly pumping a good volume of fuel. So not much left I can think to do except make taking the fuel plunger units from the fuel pump to a fuel shop to be checked? If anyone can help me in anyway it would be great as I have not got any experience on these engines
 

mickeyd

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2014 L3200 DT w/LA524 FEL, 2019 Kubota Z121S w/ 48" Pro Dec, TG1860G w/RCK54TG
Mar 21, 2014
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Guin, AL
Welcome to the forum. Sorry that I can't help but I am sure that one of the fine members here can.
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Start at the fuel tank and go through all the parts one by one and make sure you get fuel, when you get past the lift pump you will need to crank it to get fuel to flow, Make sure the fuel shut off on the injector pump is not pulled, set the throttle to 1/4 to 1/2, crack each line coming out the injection pipe and make sure it's putting out fuel, You need to get the air out of the system to get it to start. ;)
 

Craig p

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Jan 23, 2015
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New Zealand
Yes I have done this the lift pump is pumping lots of fuel and with the injector lines cracked off some fuel is squirting out but it doesn't appear to be very much or under much pressure. And yea I have got all the air out of the system and always start it on half throttle but still nothing. I have even tried running it out of a different fuel tank with a new hose to eliminate any fuel blockages because it does seem like a fuel problem.


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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,674
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Sandpoint, ID
Remove both injector lines and injectors from the motor,
Reconnect the lines to the injectors outside of head, leave lines loose enough to bleed air out, crank till fuel leaking, snug up lines, put a piece of cardboard or paper under the injector to check for spray.
Do not put your hand in the path of the injector!
If you get spray out of both then most likely it's not a pump or fuel delivery issue.
I would then pull the valve cover off and check for valve movement.
 

Craig p

New member
Jan 23, 2015
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New Zealand
Good idea thanks I just tried it and only number two was spraying swapped the injectors and still only number two port from the pump was spraying so it's not an injector fault it's definitely in the pump. Pulled the top section of the pump off and the cam lobes and followers look fine so I guess the problem must be in the pumping unit above the follower? But can't get this apart to swap the two to
Confirm this as you need a special hollow point torx bit to pull it apart.


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josephmhill2

New member

Equipment
Z482
Sep 23, 2018
2
0
0
McCall, Idaho, usa
Hello All,

I recently purchased an off grid cabin nestled nicely in the mountains just above McCall IDAHO, in a place called, Secesh. We have solar, batteries and had a functioning Multiquip DA-7000ss whisperwatt generator we used often to charge up the batteries when needed.

So to develop a bit of background and details that might help you, help me. The generator is powered by a Kubota Z482 hours on it, recently had the oil changed, and air filter changed a few weeks prior to my engine losing 50% of its power.

It is easy to hear that there is marked decrease in power, and by looking on the inverter, it is reading about 60 volts being produced, half of the 120 required to charge the batteries.

I spent a small fortune in American money to come out and hopefully repair it, he said I had 3 bent valve stems and that it looks like there was 4 tiny flecks of aluminum on the right port. I could see tiny specs, half the size of a pin head each. Another buddy of mine and I pulled out the stems and re-rolled them, they looked fine. He said I should take it to Boise and have it serviced, which after a phone call, the estimate is up to $6500.00 to replace it with a new engine. Really?

That seems like highway robbery, a new unit is $7500.00, so I am hoping someone can help point me in the right direction. I replaced both fuel injectors as well as the fuel pump. Bleed the lines of air, the best I could, never having done this, I did what seemed logical. The new fuel pump definitely produced more fuel out of the nozzles than the previous pump, but once fired up it changed nothing in its current condition. Still running at 50% of power.

Help!! What else can I investigate, replace, or do to identify the source of the problem... winter is on my door step here, it***8217;s 27 degrees in the morning and snow will start to fly soon.

Thanks
Joe
 
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North Idaho Wolfman

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Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,674
5,099
113
Sandpoint, ID
Greeting from north of you. :D

Have you done a compression test?

That should be first.

Then feed fuel directly to the injection pump via an overhead line or bottle and line, bypassing any other fuel delivery.

How is the throttle controlled? electronically?

If the throttle is going full open then it's either fuel or governor that is causing the issue.

FYI: I've worked on a bunch of these engines and have never see a valve bent unless something gave way majorly like a broken piston, rod or crank.
 

josephmhill2

New member

Equipment
Z482
Sep 23, 2018
2
0
0
McCall, Idaho, usa
Thanks responding so quickly!

I have not done a compression test, no idea how I would go about doing that or testing to see if in fact that is the problem. Is it possible I could loose compression in the middle of using the generator and end up with this situation?

I will need to figure out how to feed fuel to directly to the injection pump, I think I understand the concept.

The throttle seems to be self governed manually, it does not appear to be electronically controlled, could be very wrong however. It is suppose to run at an ideal speed of 3600 rpms, which it seems to be doing, it does seem like one of the pistons is not getting enough of something. When I manually increase the throttle, the power does increase to where it needs to be, but that is not the intended method of operation.

Thank you thank you for your time,

Joe
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,674
5,099
113
Sandpoint, ID
Thanks responding so quickly!

I have not done a compression test, no idea how I would go about doing that or testing to see if in fact that is the problem. Is it possible I could loose compression in the middle of using the generator and end up with this situation?

I will need to figure out how to feed fuel to directly to the injection pump, I think I understand the concept.

The throttle seems to be self governed manually, it does not appear to be electronically controlled, could be very wrong however. It is suppose to run at an ideal speed of 3600 rpms, which it seems to be doing, it does seem like one of the pistons is not getting enough of something. When I manually increase the throttle, the power does increase to where it needs to be, but that is not the intended method of operation.

Thank you thank you for your time,

Joe
Joe,
The more information the better the diagnosis. :D

Sounds like you have lost an injector, could be from the pump could be from the injector.

Simple test: Pull both lines off the injectors and injection pump, set the throttle to high and crank you should see a fountains of fuel out of the injection pump see if they are about the same height and of good height, that height varies and is not real important.
If they are the same height then install one line off of the injection pump away from the engine, install one injector loosely, crank till fuel comes out to bleed then snug injector, check for spray pattern, DO NOT put your hand or anything else under the injector. Check both for fog, pattern, and drips.
 
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