Where did I Screw Up? Genny No Start

Setup:

1988 Onan 8K MDKC Genny with a 3 cylinder Kabuta Engine.

Getting ready to steam north to the Inside passage. So time to change the Oil and filters. So below is the process I used:

1. Started Genny to warm up oil. Ran great.
2. Drained oil and replace oil and oil filter. (I did not prefill the oil filter)
3. Turned off fuel supply and changed secondary fuel filter. I DID prefill fuel filter.
4. Turn on fuel supply.
5. Cranked genny (solenoid pulled back) and no go. Would not start. Cranked a few more times and nothing.
6. Dropped fuel filter, filter is full.
7. Dropped oil filter and is really full (big mess)
8. Thought I might have air in system, so I bled the injectors. No fuel after multiple cranks and almost a dead battery.

According to the book, after replacing the fuel filter (empty):

"Disconnect the starter solenoid lead at the FASTON terminal connector (this connector is on the starter solenoid). This allows the fuel pump operation without cranking the engine. Depress the Start switch until fuel purges at the bleed screw and bleed plug opening."

The filter is already full. The genny has always started before after replacing the fuel filter pre-filled. Could it have been the oil filter no full? There were no low oil pressure issues and the oil filter is now full.

What do you think I screwed up?

FYI: I have the "guy" to come look at it on Wednesday to look at it.

I don't know your engine, but sounds like air in the injector tubes. I have an Onan 14kw MDL-3 and if you crank with air in the system it eventually gets into the injector tubes. Loosen all the nuts on the top of the injectors and place rags around to catch any diesel. Crank until clear fuel comes out.
With air in the tubes, it compresses instead of pushing fuel out the injector. Injectors have a spring loaded valve that only opens under high pressure.

If you're not getting fuel out of the tubes you probably have a stop solenoid failure.

Thru hull closed so you can’t hydro lock the engine?

Conntrol system is working if run solenoid pulls back.

Close off seacock

Unplug elec fuel pump and rig a jumper to 12v source. Let pump run several minutes.

Try a start. If no go, crack 17mm nuts on injectors and crank til it spits. Snugs nuts and try a start.

If you have cranked the snot out of it, muffler could be full of water (or worse), see if there is a drain down on the side/bottom and drain it.

If it starts, don't forget to open sea cock.

Injection pump is self bleeding, to a point. If full of air the elec pump will get most out but sometimes you need to crack inj nuts. No other bleed points need be used.

Make sure return fuel valve is open. If shut, it can keep inj pump from bleeding.

Can you hear the fuel pump running? I have the same genset and the fuel pump lost a seal and filled the pump motor with fuel so immersed in fuel it would only run a minute or two and quit. I bought one of those electric pumps from a hot rod store (way cheaper than marine and WAY cheaper than Cummins) and it works fine. Generator 100%. By the way, I don’t think it’s a Kubota but it is a Japanese lawn tractor motor that also starts with ‘K.’ Now I’ll have to Google it, my memory...

Shibaura! Not Kubota. Not ‘K’ either. Now I’m not sure it wasn’t a 12kw Northern Lights.

Rats. Have a look at the fuel pump anyway, they are easy to pop open and if there is any fuel there, get a new pump. Still amazes me that motor brushes still work immersed in diesel and no fire.

Alaskan,
As part of your fuel filter change, did you close off your fuel inlet line at the tank (or anywhere else along the way)? If so, did you remember to open it again??
I know, simple, but some times we overlook the very basic things.
Personally I don't think the oil change is the cause of this. It must be fuel related, or something else "packed it in" as just a matter of "bad timing". If that is the case, it may be harder to figure out as your focus will be on the changes you made.
Good luck,
Tom
OOps, re-read your post and see that you did say you turned the fuel supply back on.

Larry M said:

Thru hull closed so you can’t hydro lock the engine?

Click to expand...

Close the thru hull? Never heard of this. Why?

Xsbank said:

Can you hear the fuel pump running? By the way, I don’t think it’s a Kubota but it is a Japanese lawn tractor motor that also starts with ‘K.’ Now I’ll have to Google it, my memory...

Click to expand...

I can not hear the pump running. Never have.

Its a KUbota according to the manual.

Ski in NC said:

Conntrol system is working if run solenoid pulls back.

Close off seacock

Unplug elec fuel pump and rig a jumper to 12v source. Let pump run several minutes.

Try a start. If no go, crack 17mm nuts on injectors and crank til it spits. Snugs nuts and try a start.

If you have cranked the snot out of it, muffler could be full of water (or worse), see if there is a drain down on the side/bottom and drain it.

If it starts, don't forget to open sea cock.

Injection pump is self bleeding, to a point. If full of air the elec pump will get most out but sometimes you need to crack inj nuts. No other bleed points need be used.

Make sure return fuel valve is open. If shut, it can keep inj pump from bleeding.

Click to expand...

Close Thru hull?

So I did run a jumper but only connected it for less than a minute. Can you hear the pump run? I couldn't hear it running. So run it for several minutes? Then crank it? Know about the 17mm nuts. No return valve (that I know of).

Any other advise?

Alaskan Sea-Duction said:

Close the thru hull? Never heard of this. Why?

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The entire time you are cranking and the motor doesn't start the raw water pump is filling the lift muffler with water. It is the exhaust gas from the motor running that kick the water out. Closing the thru hull stops the excess water from filling the exhaust system.

rochepoint said:

The entire time you are cranking and the motor doesn't start the raw water pump is filling the lift muffler with water. It is the exhaust gas from the motor running that kick the water out. Closing the thru hull stops the excess water from filling the exhaust system.

Click to expand...

Thank you

I'm not at all familiar with your generator, but in debugging these things, I often find that Occam's Razor is of some help. If it quit working while messing with the fuel system, it is probably something that was touched while messing with the fuel system.

I've had the no-start-after-service problem in a few ways other than needing-to-bleed on various motors over time, including two diesel generators:

(1) Valve at tank off
(2) Valve at primary filter off
(3) Tank selection valve off (or to an empty tank)
(4) Electric lifter pump turned off

...and....

(5) The O-ring on the fuel filter installed wrong. On the Perkins 6.354 and 4.107 it is really easy to accidentally put it into the groove on the top of the fuel filter, blocking the fuel ports, rather than into the groove on the top of the top part it screws into. The same may be true of your generator. The fuel filter was full -- because I prefilled it.

If it is possible on the motor, you may want to disconnect the supply fuel line from the injector pump and pump at the lifter and see if fuel comes out freely, if air or air-and-fuel comes out, or if nothing changes. Nothing much changing would point to a block, like the o-ring, versus air.

At any rate, wish I could help more. Good luck!

-Greg

You only disturbed 2 areas, and the oil part can`t be the culprit.
When I change the fuel filter, and hit start, the engine very quickly wants to run, even with the bleed screw open it runs, it`s dead easy to bleed. I had leaks at the filter housing,it would seal after replacing the filter and later leak, badly. Turned out the filter housing was damaged, but even when leaking there it ran until I shut it down. Whatever has gone wrong must have let in or be letting in a lot of air.

rochepoint said:

The entire time you are cranking and the motor doesn't start the raw water pump is filling the lift muffler with water. It is the exhaust gas from the motor running that kick the water out. Closing the thru hull stops the excess water from filling the exhaust system.

Click to expand...

To add to this, eventually the water will rise to the exhaust manifold and flow through the exhaust valves and into the cylinder. You can’t compress water and continued cracking can do severe damage.

rochepoint said:

The entire time you are cranking and the motor doesn't start the raw water pump is filling the lift muffler with water. It is the exhaust gas from the motor running that kick the water out. Closing the thru hull stops the excess water from filling the exhaust system.

Click to expand...

To add to this, eventually the water will rise to the exhaust manifold and flow through the exhaust valves and into the cylinder. You can’t compress water and continued cracking can do damage.

Alaskan Sea-Duction said:

Any other advise?

Click to expand...

Wait for expert on Wednesday. While it's likely something minor, you could just turn it into something major by trying solutions but not really knowing what the problem is. If you tried, you might hit the solution quickly, but you might just dig yourself into a deeper hole.

KISS principle-

A) Got compression? Is the timing system good/no snapped chain/valvetrain properly moving? Did you try to start with ether/starting fluid?

B) Is fuel getting to the injectors?

At the core, diesel are simple animals.

You should be able to hear the fuel pump when you jumper 12v to it. Engine room needs to be pretty quiet, though. There is a blade disconnect on the 12v supply lead to the pump, just unplug it and feed it straight 12v. Makes a click click click sound.

Jumper it with 12v and get engine room quiet and listen. If you can't hear it or feel and motion, pump may be dead. These do fail.

Also, on the side of the injection pump on some of these is a round knob valve, it is the pump bleed valve and should be open. Most don't have the valve and instead a drilled orifice in a fitting going to return line.

But if yours does have the valve and it is closed, pump won't bleed.

If I were to jump in and give advice i’d Just be repeating what ski has already said. For all others who are reading the take away is this. Do only one service item at a time. Then start to review your handy work before going to the next service item. Generators have multiple safeties. One safety is to shut down on low oil pressure. I believe ski is on the right track, I add this to point out how diagnostics can get complicated when you have to work through multiple recent changes. What ski is trying to work through now, did the fuel pump just happen to break now, is there air in the line. Once ski is convinced that there is no air in the line and the fuel pump is working and we still have a no start he will move on to looking for a sensor that has tripped and not reset.

If it has glow plugs make sure they are working. My Westerbeke wouldn’t start a few years ago and it was the relay for the glow plugs not energizing them.

Kubota. The first thing to get ragged seems to be the memory.

Mine didn’t start one time. I had been working on my batteries and I had to squeeze by the genset. Turns out I turned off the run switch on the generator without knowing it. Felt pretty dumb after I went through a bunch of troubleshooting and it was just a switch. Have you looked over everything like that?

Tom, after working your way through Ski's list with still no go, you might check the shutdown sensors, oil pressure and water temp. Last summer, my NL 5kw genset would start, run for a few minutes and then shutdown. Fuel filter was full and i had fuel to the injectors. I couldn't find the problem and had to divert to Ketchikan to get help from the NL dealer there. Turns out the water temp sensor was shutting things down even though the water temp was ok. The low oil pressure sensor could similarly be the culprit.

There’s the stop solenoid, but there’s also a speed control lever that may need to be moved also. I have an MDKD and the two times I’ve had issues is trying to start it with the glow plug switch activated and a rotted out exhaust temperature switch. Btw, I probably have a direct from the manufacturer part number for that switch. I paid under $20.

Be REAL thankful it is not a gasoline engine.

Diesel engine.... air, fuel, compression and cooling water if it is water cooled.

My question, because of my feeble mind, isn't it bleed the fuel pump then bleed the injectors. Isn't there a specific order of bleeding the injectors instead of opening them all at once?

I agree. Do one maintenance item at a time then, start and run the engine. Tomorrow is a new day.

Next time, pre-fill the oil filter. If you dont, you may have tripped the oil low pressure safety.
If you change the fuel filter, pre-fill the filters.

If you change the fuel filter, pre-fill the filters.[/QUOTE]

Some gensets have electric fuel pumps and it is best to put filter on dry and then prime the system with the electric pump. At least that is what my Onan (Kubota) MDKAW manual states.

sum escape said:

If you change the fuel filter, pre-fill the filters.

Click to expand...

Some gensets have electric fuel pumps and it is best to put filter on dry and then prime the system with the electric pump. At least that is what my Onan (Kubota) MDKAW manual states.[/QUOTE]

Are the talking about the Racor filters or the engine mounted filter?

OldDan1943 said:

Some gensets have electric fuel pumps and it is best to put filter on dry and then prime the system with the electric pump. At least that is what my Onan (Kubota) MDKAW manual states.

Click to expand...

Are the talking about the Racor filters or the engine mounted filter?[/QUOTE]

Engine spin on filters.

sum escape said:

Are the talking about the Racor filters or the engine mounted filter?

Click to expand...

Engine spin on filters.[/QUOTE]

May I suggest, you write the date and engine hours on the metal housing of the filters.

So I worked through Ski's list. Nothing. No fuel at the injectors and I "hot wired" the fuel pump for about 10 minutes.

So my next step is to disconnect the fuel filter input line (which is also the fuel pump output line) and hot wire the pump again. If I get fuel, then I will start working my way to the injectors. If I don't get fuel, then the pump is bad. I already have one on order from Amazon.