Generator 1 Second Run Issue

[MangoMike]

After reading Gordon's woes, I've seen to develop my own. Before I place the call the Kohler thought I would try the brain trust.

2000 Marathon H3, Kohler 20kw, Yanmar Engine.

Oil and coolant levels right on.

Starts and runs for 1/2 to 1 second like a champ. Then immediately dies. Absolutely not a fuel starvation issue as I've had plenty of experience with that.

It will run perfectly if I keep the GEN START button on the dash pushed in. Finger off and it stops immediately. And no, the starter is not grinding away during this process.

With some help from Trukman I unabled the Auto Start to remove that from the formula.

Where is a good point to start looking?

Thanks for any advice.

Mike

[GDeen]

Wow - you must have ESPN or something Mike. I just posted the favorable outcome of a trip to a Kohler service center while you were posting this.

Mine was a governor or speed control setting problem. I could see that also being a potential issue with your symptoms. If after starting, the speed control takes over and is not sending the proper fuel mix it could kill the engine immediately. Mine was sending too much fuel apparently. Pure backside extraction but could be plausible.:confused:

[MangoMike]

Gordon,

The more you learn the less you know. Thanks for another check point.

m

[Danss]

I had same problem with Power tech generator and it was the solenoid failing. It was the one on the Generator that activated when you shut generator down with the switch on the dash. Very inexpensive part. dan

[Alek&Lucia]

Dan,

Can you give us the part #, and where you got the replacement,

Alek

[Danss]

It was put in by Parliment and I assume they got at local Auto parts house but I do not have a clue as to the part number. Sorry. Dan

[MangoMike]

Kevin Erion wins the Jerk Chicken Dinner via parcel post for his correct diagnosis of the problem.

Failed Injector pump fuel solenoid.

5968
This is the solenoid removed.

5969
Side of the injector pump. You can put your finger in the hold to manipulate the fuel valve to see if the engine will run. I have to admit I didn't try this, but saw the tech from Kohler succesfully make it happen.

5970
This is with the solenoid in place. This is now an internal solenoid setup.


On the older gensets this was an external setup and you could see the actuator arm extend from the solenoid into the side of the ejector pump to verify it was working. On my unit w/ the internal setup you had no way of knowing if the solenoid was working or not.

[Kenneth Brewer]

Gordon,

The more you learn the less you know. Thanks for another check point.

m

What Mango said. Thanks.

[MangoMike]

Kohler installed a new solenoid today, which they swore was the problem.

No go - so Kevin send back the Jerk Chicken.

Will post results after they repost on Tuesday.

[Jerry Winchester]

Maybe it's the power going to the solenoid? It would act the same, but changing the unit wouldn't matter.

[MangoMike]

Dub,

He thinks it's probably just that, some relay that activates the solenoid. Unfortunately due to the location of the control box he can't get at it to test it. I have to rig some way we can extend the genset out of the bay more for access.

[Jon Wehrenberg]

I am not an expert in this and have never had to trouble shoot a generator problem, but logic suggests if the solenoid is good (just verify it with an OHM meter) then look to the converter installed starting circuit.

All of the generator controls in our coaches stop the generators by opening the circuit to the solenoid.

[Jerry Winchester]

Just get a ninja to slip in behind the generator...........

[Orren Zook]

If your genset is on a track like those on a Liberty, you can use a floor jack (on wheels, of course) or a truck transmission jack for support to slide it out of the bus. I've seen both used - the transmission jack looks to be the best choice if you have access to one, they're infinitely more adjustable when it comes time to put the generator back in the coach.

[jello_jeep]

I found that mine will shut down if "auto-gen" is engaged and you try to manually start the generator. Starts up ok, but shuts down in a second or two.
Not likely your problem, but add it to the list.

[stevet903]

Mike - My Kohler/Yanmar 14.5 KW has a low oil pressure and a high temperature switch that will shut down the engine if the oil pressure is low or the temp is too high. It will open the fuel solenoid and the engine will not run. These are bypassed when the starter switch is pressed - the engine needs to spin for a couple of revolutions to get the oil pressure up. My guess is that one of these switches has failed. On mine, the water temp switch is located on the gooseneck on the top right side of the engine, the switch is on the left and the temperature sender is on the right. The switch should have either zero resistance or will be open (it should be open). The temperature sender will have a range of 100-250 ohms depending on the temperature. The oil pressure shutdown switch is above and to the left of the dipstick. This switch is normally closed - the oil pressure opens it. There are a couple of relays in the controller cabinet that could be bad as well - the opening and closing of the relays are controlled by the switch positions of these plus the start/stop switch, remote start stop, etc.

Hope this helps....

Steve

[MangoMike]

Steve,

We already tested the sensors and they passed the test so next step is inside the control box.

Orren,

Great excuse to buy another tool. I'll be heading down to Harbor Freight today.


Jon,

When all else fails, I'm coming to knoxville.


JDUB,

5984

[Jon Wehrenberg]

Mike,

As I said previously I have no clue about the various generator start and run circuits because to date I have not yet had to dig into a problem, but from the description you have given it sounds like something within the generator control circuitry or the converter start circuitry something is opening the circuit to the solenoid.

Since the engine related sensors such as oil pressure and coolant temp sensors have been checked it points in that direction. I also assume the generator has some sort of diaphraghm switch that signals when the generator is running (via a manifold vacuum usually) and disengages the start mode. If not look at that as well because that is central to this issue.

We are all going to learn when you find the problem.

[sawdust_128]

Is that the Mango Mike's salad girl?

[MangoMike]

Jon,

THe Kohler tech did say there was some sort of shut down procedure if the system senses the generator is not developing sufficient output. We'll be checking that on Tuesday.

More to come...

Mike

[MangoMike]

Orren,

Picked this up today. Figured I could get multiple uses out of it and priced cheaper than a Transmission lift. $99.

5985
Harbor Freight #2792

[Jon Wehrenberg]

About a month ago I could have used that to remove and replace my 8D house batteries. Without it I had to balance them on a hydraulic floor jack. It worked the way I did it, but your motorcycle lift would have made it much easier.

Where was that when I needed it?

[MangoMike]

About a month ago I could have used that to remove and replace my 8D house batteries. Without it I had to balance them on a hydraulic floor jack. It worked the way I did it, but your motorcycle lift would have made it much easier.

Where was that when I needed it?


Don't you usually strap that stuff to Fast Roger's back?

[Jon Wehrenberg]

He's still busy trying to bling up the CC so he wasn't available to do the heavy lifting while I supervised.

I don't think he would have wanted to help. I sold the old batteries for scrap and found they weighed 170# each. If I knew that before I started I would have delegated the responsibility.

[truk4u]

Thats what I use and if you two were Bikers, you would already have that in stock!:rolleyes:

[GDeen]

Thats what I use and if you two were Bikers, you would already have that in stock!:rolleyes:

Had the craftsman version for about 5 years now Truk - pretty handy!

[Orren Zook]

Orren,

Picked this up today. Figured I could get multiple uses out of it and priced cheaper than a Transmission lift. $99.


Well done!

[MangoMike]

I think I paid a lot education dollars.

About 12 hours of work over 4 visits to finally find the problem. There are two inline fuses buried in the control box attached to the generator. One was blown (250v / 8amp Slow Blow) and we thought that was the problem. Changed and immediately blew again.

Finally traced it down to the voltage regulator board also located in the control box. Haven't seen the price yet on that board.

With all the hours spent trouble shooting I just wonder in the future if it's just cheaper to change the boards. Plug and pray.

This is the only authorized Kohler dealer in the area and they handle the work for 4 states.

Mike

[GDeen]

I think I paid a lot education dollars.

About 12 hours of work over 4 visits to finally find the problem. There are two inline fuses buried in the control box attached to the generator. One was blown (250v / 8amp Slow Blow) and we thought that was the problem. Changed and immediately blew again.

Finally traced it down to the voltage regulator board also located in the control box. Haven't seen the price yet on that board.

With all the hours spent trouble shooting I just wonder in the future if it's just cheaper to change the boards. Plug and pray.

This is the only authorized Kohler dealer in the area and they handle the work for 4 states.

Mike

Well that sucks....Hope you are finally healed.

Voltage regulator was Leon at Marathon's first guess on my problem. Am also hearing that a shaft bearing failure is fairly common in these things at 3-4k hours so that is something to keep an eye on.

[Kevin Erion]

I have been told that the shaft bearing is something to look at around 5000 hrs. I got that from the owner of Martin Diesel that supplies lots of generators to different builders.

[rahangman]

I just had a new Regulator Board for my home Generator System (Onan) replaced. Onan's price was twice what GCM Computer Systems of Fayetteville AR was able to provide a new card engineered and gave me a 2 yrs warranty over 1 year from Onan. Might want to give them a call if it is the board itself. www.gcmcomputers.com

[MangoMike]

I just had a new Regulator Board for my home Generator System (Onan) replaced. Onan's price was twice what GCM Computer Systems of Fayetteville AR was able to provide a new card engineered and gave me a 2 yrs warranty over 1 year from Onan. Might want to give them a call if it is the board itself. www.gcmcomputers.com

Too late now, but thanks for the reference. Will catalog it for the future.

Mike

[MangoMike]

I have been told that the shaft bearing is something to look at around 5000 hrs. I got that from the owner of Martin Diesel that supplies lots of generators to different builders.

What are the symptoms of this failure, and any idea of repair cost?

m

[GDeen]

I have been told that the shaft bearing is something to look at around 5000 hrs. I got that from the owner of Martin Diesel that supplies lots of generators to different builders.

So-Tex, repair facility repping most of genset manufacturers gave me the 3k hour number, and a generator repair shop in AR gave me the 4k number so it must be somewhere in that vicinity. So-Tex claims due to low quality Chinese bearings.

My main point is, for a machine that is supposed to easily reach 30k hrs with routine maintenance to have a major bearing failure somewhere in the first 10-20% of its service life is worth knowing and monitoring.

Mike, my generator was shaking and the owner of SoTex first thought was bearing failure when I talked to him over the phone. After his evaluation, he came out with a speed control correction as curing my problem, and I never got an estimate on replacing that bearing. Probably will though next time I have any service work done on the generator.

[Jon Wehrenberg]

What's a shaft bearing? Crankshaft? Camshaft? Have a bad crank bearing, or if one spins that's in the league of engine replacement. What's unspoken is which engine. We have Kubota, Yanmar, etc. Certainly not all brands are impacted.

I agree with Gordon. Something stinks because these generators should easily go 30,000 hours with routine oil and filter changes. That information comes from two sources, one of whom has run many of them on coaches.

[Kevin Erion]

I believe it's the bearing in the generator side.

[Charles Spera]

At about 4000 hours my generator was fitted with a new bearing that supports the generator rotor. A recent visit to Martin Deisel Generator for a check up showed this bearing to be still good but we replaced it again anyway. The cost of the bearing is about $30 but the install is a bit pricey. The alternative is a rather expensive generator head.
I have a Yanmar gen engine....with care it will last nearly forever!
HTH
Keep safe

[GDeen]

Charles just described it Jon - on the generater side...

I would like to have it replaced sometime so as not to have a failure while dry camped in August which is when it would likely fail.:rolleyes:

[Jon Wehrenberg]

Generator side on Martin Generators? Or is this across the board?

It's not like I have a ton of hours on mine, but I think for general knowledge all POG members would be interested in knowing if this problem is associated with one brand or all.

[Kevin Erion]

Jon, Martin Diesel builds the unit using a spec motor such as Yanmar or Kabota and the generator side is a Marathon. I think a Power Tech is very similar. I think most all of the better units use a Marathon for the AC generator side. It's my understanding this bearing is on the Marathon side and the service interval will be the same on most of our generators.
Having said that Jim at Martin Diesel is a great guy and I have used him a few times on the generators we used in our race transporter trailers. The only down side for me is he is in Defiance, Ohio but worth the trip if you are in the area!

[scott13]

Check the voltage going into that control box for the generator. I understand that if it's not getting 12 volts the generator will shut down.

[Jon Wehrenberg]

I think as a general comment, if the generator is not getting 12 volts there is a much more serious issue at play here. With all our various systems (chassis 24 and 12V, house DC (12 or 24), house 120 VAC, plus the myriad of chassis and generator values ranging from oil pressure, air pressures, coolant temps, etc. owners need to be constantly vigilant.

[pwf252]

Along the line of one's generator starting and then immediately shutting down mine does exactly that but then within a few seconds it cranks back up. This process happens after pressing the start gen. button one time. Could this portend to future issues? Anyone elses generator act the same?

[rfoster]

PATRICK:
My Gen set behaves exactly the same way. I believe it may be designed to do so in order to do a "systems check". Only no computer talks to you.

[pwf252]

Roger,
Thanks for the info. Sounds like maybe its a Country Coach thing. I'll find somrthing else to worry about.

[BUSTER]

This is on sale for $69.99 if anyone needs one.

Harbor Freight #2792-VGA

[tdelorme]

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=2792

[GSwaim]

Just to let others know, I found the problem on my PowerTech 17.5 Kw generator. It would only run for a second then shut itself off. I ended up finding the radiator fluid level sensor bad in the top of the radiator. the sensor doesn't show on the schematic but has a ground lead toi the head and another lead running to the control box. The way the sensor works is with a low fluid level condition it sends a ground signal to the control box that doesn't allow the genrator to run. If the radiator fluid is full the sensor then sends an open signal to the contol box. During my troubleshooting I jumpered the oil pressure, high temp and this fluid level sensor and the momentary run symptom remained. When I cut the lead going to the fluid level sensor the symptom is gone. I'm guessing that the sensor is stuck even though the fluid level in the radiator is fine. Since I can find no mention of this sensor in the manufacturer's manual I thought I would pass on this bit of knowledge.

Gary

2002 Royale

[GDeen]

Good dective work Gary - not sure I am smart enough to figure out a shut down switch not in the drawings. Thanks for the heads up.