Multi Symptom Generator problem

jmacstack · 06-04-2009, 01:57 PM

I have 20 Kw Kohler Generator in my 1987 Newell. Here's the issue: Sometimes it will start up just fine from inside the coach or at the generator itself. If I shut it down and try to restart, it will run at slow idle and run for a few seconds, up to 30 seconds(appx) and then shut itself down. This happens hot or cold. During this slow idle period, I am unable to shut it down using either switch. Sometimes when I try to fire it up, I get nothing but a click. I fired it up the other day to go 3 miles to a business and when I got to my destination, it had shut itself down. When I was running it those 3 miles the oil pressure gage on the instrument panel for the generator was pegged off the scale. I have replaced the merge solenoid. I have replaced the fuel relay in the controller box on the back of the engine. I have recently changed the oil and all fuel filters. I have cleaned all grounds I could find. All fuses are good. House batteries are charged. Does anyone have any clues about what I can try next? Thanks, Jennifer

encantotom · 06-04-2009, 03:16 PM

hi jennifer. a few questions.

1. a 20kw generator is not the normal one in a 87, a 12.5kw one is. so is the engine a yanmar? once you get it working, i have some questions about how it is integrated into the coach, but those are for later.

2. a simple question, but you are using the switch to "warm" up the glowplugs for 30 seconds of so before you start it, right?

3. when did the problem start? after doing any of the service?

tom

Richard and Rhonda · 06-04-2009, 03:23 PM

Jennifer,

Look at the solenoid that turns the fuel off and on. I had similar issues. Mine would start and stumble. And then one day it wouldn't stop running. It turned out the rod from that fuel solenoid to the lever on the fuel injector pump had come loose.

The solenoid is kind of hidden, but it is on the side of the engine with the injection pump. Look for a round solenoid, an adjustable rod coming out of it that is connected to lever that moves back and forth.

I'll send you a PM with my cell.

HoosierDaddy · 06-05-2009, 02:24 AM

Hi Jennifer,
I would investigate the oil pressure gauge issue. I think it is set up so that if the oil pressure drops it will shut the engine down. Check oil level and viscosity first, then the oil pressure sender and related wiring. I have found that my '78 Newell relies on 12V from the chassis batteries to activate the fuel solenoid.
Good Luck,
Dean

HoosierDaddy · 06-05-2009, 02:36 AM

Also...My 78 has a glass fuse located on the back side of the front panel of the box on top of the generator (12Kw Kohler/Perkins). You cannot see the fuse. I was having similar start/run problems when a bit of corrosion caused an intermittent 12V supply through that fuse. I found that there was no 12V supply at the dash switch when the fuse was malfunctioning.

jmacstack · 06-06-2009, 02:06 PM

Thanks for all your ideas. Tom, this coach was re-powered and yes it is a yanmar engine. I serviced this with the previous owner in Ohio,(Walter Preston) before we headed home to Montana. All systems were good to go. The problems started in Iowa.

Dean, I have isolated my fuel solenoid power origination and it is from the house batteries. I have checked and re-check that glass fuse.

Here are some more thoughts: I have zero resistance to the hold in coil at the fuel solenoid. I do not have 12 volts from the control box to that lead. How is this possible? If I had power I should have no resistance. Early on in this dilema, I checked the house batteries. There was no noticeable water in ANY of the center cells of ALL batteries and there was a bit of water in the rest of the cells. I put almost 4 gallons of distilled water in these batteries which are 5 years old. Could this be the culprit? I have not had them load tested. I now have the coach plugged into 50 amps and am waiting to check on if they can receive a full charge. I may have to replace them. The 2nd leg light on the panel above driver's seat is flickering and the other leg light is strong on.

Richard, I have ordered a new fuel solenoid to the tune of $238.00. Seems a bit steep to me. However, if I am not getting 12 volts to the hold in lead of that solenoid, replacing it will be futile. I was recently told that 6 volt deep cycle batteries are better than 12 volt. Currently I have 12 volt. If I have to replace the house batteries, should I replace them with 12 or 6 volt?

Thanks for weighing in on this head scratcher. Jennifer

fulltiming · 06-06-2009, 03:35 PM

I am not sure which batteries the 87's used. If they are 4-D's or smaller, changing to twice as many 6 volt golf cart batteries would work well for the house batteries. The 90's models use 8-D's and I have had great luck with the AGM 8-D's. They are expensive and heavy but they hold up well.

encantotom · 06-06-2009, 04:04 PM

gee, maybe having been in iowa was the issue? sucked some corn in the genny? (thats from an iowa boy). the coaches i have seen of that year have had 8D's. with the coaches that have battery boxes versus pull out racks the issue is making any battery other than the original size fit in that box.

wallys 88 has has battery boxes that stick up, mine are recessed. i considered putting a different one in but it wasnt going to fit. so i found a deal on 8D AGM's of 400 each and put them in the coach side. i was a cheapskate and put regular batteries in the starting side and got them at Sam's club for if i remember right about 130 bucks apiece. interstate brand.

btw, the 8D's weigh over 150 pounds apiece, so get some help to take them out and put them in. the 6v deep cycle are easier to find by far but you will have to make new battery cables as well.

the lead acid batteries do not like to be charged with no fluid in them and will destroy themselves. if they were dry and had been charging, good chance they are toast. load testing is not as easy as you would think since you either have to drive the coach somewhere and unhook the battery or take it somewhere.

the flickering light on your panel is nothing more than the light ending its useful life. i have replaced all mine and most of the gang here has replaced a few of them. they are 2-3 bucks each if you know where to buy them. (we can help with that)

tom

fulltiming · 06-06-2009, 04:14 PM

Jennifer, you mentioned that you had double checked the glass fuse. I would try replacing it. I have seen fuses that looked good, ohmed out OK but failed under load. Not typical but it can happen.

Richard and Rhonda · 06-07-2009, 11:26 AM

Jennifer,

Disconnect the arm on the solenoid and open and close the fuel shut off arm manually to see if that remedies the problem. If it does or doesn't that will help in the diagnostic.

Wally Arntzen · 06-07-2009, 04:23 PM

Jennifer, my 88 has 8D batteries. I replaced all of them with Catepiller maintainance free ones and also use the power pulse battery saver to extend the life of them. These batteries cost in excesss of 550.00 each but are super batteries. I have been using the power pulse saver long before Newell started putting them in all of there coaches. They are less that 100.00 each and they really do extend the life of a battery.
Tires and batteries are costly items but both are extremely necessary to be in good condition when running these coaches.
There are a lot of options on batteries but I strongly recomment that you get as good a battery as you can afford.

Thats my opinion and i'm sticking with it.

Wally

ps, Tom is a good friend who has spared no cost to make his coach beautiful with no cost sparred and I don't understand why he admitts he put in cheap batteries. LOL

prarieschooner · 06-08-2009, 01:56 AM

Changing out Batteries can be a very expensive proposition and you just purchased the Coach. Basically there are two types of House Batteries that I would choose Flooded Lead Acid (one that you add water to) and Absorbed Glass Mat (AGM).
When you stated 6 Volt you were most likely talking about Golf Cart or Deep Cycle Flooded Lead Acid Batteries. This type of Battery is relatively inexpensive while the Charging System of your Coach is probably already set up for them.
The AGM is a sealed Battery and has an Extended Life if taken care of properly and these are getting more popular. The AGM Battery is much more Expensive and the Charging System should be set up for this type of battery.
When you get to the Staring Batteries I am not sure that it is worth the Extra $$$ to go with AGM Batteries. A good pair of 8D Batteries is hard to beat and you can get a deal on them at any Battery Dealer. I paid about $125.00 each for a Commercial Grade and plan on changing them out in a couple of years.
For the House I chose to use TROJAN T105 6 Volt Batteries and paid around $125.00 each with a total of 4. These are much easier to lift than an 8D and usually last much longer if taken care of (check the level and use Distilled Water). These should last between 3-5 years with care but I have some that were installed on my Boat that are still in good condition after 7 years.
Since you just bought the Coach I would recommend that you replace the Batteries with ones of the same type. You can always up-grade to the AGM type in a few years and they will most likely be less $$$ because there are more resources for this type of Battery every day. You will also be able to replace the Charging System over time and not need to incur the Cost of replacing both at the same time.
This is my Opinion and like Elbows we all have them.

encantotom · 06-08-2009, 04:18 AM

I did put in AGM batteries as i said in my coach side. i was able to find a smokin deal on them of 400 each, but i did have to make new battery cables as they were lugs versus A posts, but i kept the old cables so i can switch back if i need to.

the "cheap" batteries were still high quality interstates for the starting side. it would have been nice to put agm's there too, but as wally said, i have spared no expense in many regards in refurbishing my coach, and i chose to put the money elsewhere....oh yeah, that was for my kids in college....

put agm's in the coach side and it will be best as long as your charger can charge the agms right, for the starting side do what you can afford and feel good about.

i also put in the power pulse units on each bank of batteries. i know wally has one on each battery, so he gets double goodness. they are supposed to make the batteries last twice as long by desulfiding them.

or do whatever you want as long as you feel comfortable with it.

and as wally has taught me to say....thats my 2 cents worth and i am sticking to it"

btw, wally has really spared no expense on his coach as it is BEAUTIFUL and has lots of upgrades he has done.

mine is just a heavy camper in comparison......

tom

jmacstack · 06-19-2009, 11:28 PM

Hello to all who have have shared their ideas, questions and expertise on my multi-symptom generator problem. Here is the solution!

1. Purchased 6 new 12 volt deep cycle batteries for the house. Ouch!
2. Added a batteryminder. Well worth the $99.00(Northern Tool)
3. This generator has 1304 hours on it. I was looking hard at the fuel solenoid, the K25 relay which feed the fuel solenoid(replaced with new) and possible causes of low-voltage to the control box. Here's the fix: The fuel solenoid arm is attached to the fuel solenoid on one side(left) and the other side(right) is linked directly into the fuel pump. The shaft inside the fuel pump has a spring and a(shoot can't remember what it's called) but it fans in and out in a circular motion to activate and de-activate the fuel pump. This particular apparatus spins on this shaft. If the generator is run for long periods of time with no load variation the shaft will wear a groove around in one spot causing this circular apparatus to hang up in start up as well as shut down on the groove that is created by constant spinning in one place. The repair is a removal of that side of the fuel pump and rebuild and re-install. The action of fuel solenoid arm is very sticky and does not feel springy at all. Since I ordered a new solenoid I knew what it was supposed to feel like. There is also a spring in that side of the fuel pump which could break which would cause the same symptoms and stickiness.

Lesson: Do your laundry, turn on all lights, watch TV and cook all at the same time to load that genny up!

This repair has been a head scratcher and I hope posting the solution will help someone else from going bald! Thanks a million for all you help! Richard you were in the right area right out of the starting gate!

Richard and Rhonda · 06-20-2009, 01:24 AM

Absolutely,

Thank you so much !!!!!! Not only did you post the fix, but you gave plenty of details on what to look for. YOu have officially lost your rookie status :-)

You rock !!!

My gennie is sometimes recalcitrant on starting, and I have focused on the solenoid. I now will move it by hand and see if it has the sticky syndrome.

encantotom · 06-20-2009, 01:49 AM

Richard is always spot on. thanks Jennifer for posting what fixed it.

it is great to have another person to guide us on how to fix stuff.

later

tom

tuga · 09-19-2010, 09:34 PM

My generator problem is a little different:

1. In 93 degree ambient temps my gen runs at 210-225. It will run for 48 hours like this. However at night it does run at 180 when ambient temps fall to 77 degrees.
2. If ambient temps get hotter it shuts down at about 230 degrees; this is probably right.

This morning, after running for 48 continuous hours, it slowed down, strained a little, then died. Ambient temps were 88 degrees and since it was early morning the operating temps were 175-180. I checked oil and water - all o.k. I started it up and it ran for another 30 minutes (operating temps 175 degrees) ambient temps 88 degrees. It stopped again after about 30 minutes so I just left if off.

It used to run all day at 180 with ambient temps 70 degrees
then 200 with ambient temps 80 degrees
then 210 with ambient temps 90 degrees
then 225 with ambient temps 93+ degrees

So it looks like I have TWO PROBLEMS:

1. Overheating during hot ambient temps
2. Shutting down for no apparent reason

Any suggestions?

chockwald · 09-19-2010, 10:08 PM

I'm assuming your genset is a diesel, so I'm not sure what optimum operating temp should be, but 220+ seems high. I would not think it should go up that much even with temps in the 90's. Mine, which is fueled by propane, runs constantly at 180-185 when it is 70-100 outside.

HoosierDaddy · 09-19-2010, 11:48 PM

Tuga,
Shutting down sounds like a fuel problem. I would check:
the fuel filter etc.
the fuel rod solenoid
the Murphy switch

It seems that the cooling ability is marginal so it might be time for cooling system maintenance. I dont think it should ever run over 200. flush and clean radiator, new thermostat, belts and hoses, water pump. Check squirrel-cage fan..make sure it is running up to speed, belt, bearings etc.

These two problems may not be related.

fulltiming · 09-20-2010, 02:16 PM

I concur with Dean. Your generator should not be running that hot so the generator radiator and fan would be the two primary suspects. I find that load makes more difference than ambient temperature on the generator's operating temperature. With only 2 air conditioners on, mine will run at about 180 degrees at 80 degrees or 100 degrees outside. When I turn on all four airs, the temp will go up.