Generac generator (natural gas) starts but won't stay running

[TOM]

It will only run for about 8sec's then stops. It does it 4 or 5 times then
shuts down.

--
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[Jack Goff]

On 09/06/2013 02:44 PM, TOM wrote:
> It will only run for about 8sec's then stops. It does it 4 or 5 times then
> shuts down.
>

Maybe it is sensing low oil pressure and shutting down?

[hrho...@sbcglobal.net]

On Friday, September 6, 2013 1:44:01 PM UTC-5, TOM wrote:
> It will only run for about 8sec's then stops. It does it 4 or 5 times then shuts down. -- posted from http://www.homeownershub.com/maintenance/generac-generator-natural-gas-starts-but-won-t-stay-runnin-762399-.htm using HomeOwnersHub's Web, RSS and Social Media Interface to home and garden related groups

Are you sure the gas supply can keep up with the needs of the generator? How old is the unit, when did it last run satisfactorily, etc, etc.

[The Daring Dufas]

I had to replace a lot of defective oil pressure sensors on Generac
gensets for that reason. I had forgotten until you brought it up. I
tested for that by disconnecting the terminal from the post on the oil
pressure switch and making sure there was sufficient oil in the
crankcase started the generator. If the engine ran with the oil pressure
switch disconnected then stopped when the wire was shorted to ground,
that indicated a problem. The switch shorted the connection to ground
when oil pressure was lost. There is a time delay allowing oil pressure
to build up and open the connection when proper oil pressure is reached.
With the engine running, use an ohmmeter set to the lowest scale, the
switch should test open with the engine running. I found that the big
old oil pressure switches meant for older automobile oil pressure lights
worked better than the OEM replacement available from Generac
which was a cheap dinky little switch and it was a very common failure
point on their gensets. ^_^

TDD

[Stormin Mormon]

Another moaner....

.
Christopher A. Young
Learn about Jesus
www.lds.org
.

[cl...@snyder.on.ca]

On Fri, 06 Sep 2013 18:44:01 +0000, TOM
<caedfaa9ed1216d60e...@example.com> wrote:

>It will only run for about 8sec's then stops. It does it 4 or 5 times then
>shuts down.

Check the low oil shutdown switch (and the oil level)

[tra...@optonline.net]

Could be something simple like that. Or it could be more
serious. I went through diagnosing one last year that also
started up, ran for some number of seconds, maybe 10 - 15 secs
or so, then shut off. As I recall, a few things happen
around that time. One is that upon starting, the ignition
voltage is supplied by the battery, but then after starting,
it switches to being supplied by one generator winding that
serves that purpose. If that winding or associated circuit
is bad, it loses ignition. Also, as I recall, the generator
control looks for normal voltage after start-up. If it doesn't
see it, then it will shut it down.

In the generator I had, it was a bad rotor for sure, and
possibly a bad stator too. I took a look at all the complaints
on Amazon about similar Generacs and concluded it wasn't worth
fixing. That had also been the conclusion of the service guy
who diagnosed it for the neighbor I got it from. Being that it
was only about 5 years old, I thought I might get lucky and be
able to fix it, but it didn't pan out.

I found the Generac service manual online which had good detail
on the various test procedures.

[tra...@optonline.net]

Also, the unit here had a couple of fuses that were accessible
right at the control panel. Checking them is quick and easy.
As another simple test, if you're comfortable working with AC,
put a test meter on the generator output. If you have 240V
during the time it's running, then you know the generator
section is working. If not, then you know you have bigger problems.

[Dave]

replying to The Daring Dufas, Dave wrote:
Oil light stays on and it keeps shutting down

--
for full context, visit https://www.homeownershub.com/maintenance/generac-generator-natural-gas-starts-but-won-t-stay-runnin-762399-.htm

[Cyndi Jacobs]

> >"Lay the screwdriver on one of
> >the big contacts that the transformer has and then get the end of the
> >screwdriver very close to the other one.  You should see a contnouse
> >spark from the other one to the tip of the screwdriver."
> >
> >Come to think of it, maybe the reason he's not reporting back is
> >you killed him.
>
> You're a trip.
> >

And you're a dangerous idiot.  Somebody shows up here, basically says my furnace starts and only runs for a few seconds, shows no indication
of having *any* technical knowledge of dealing with an oil burner
and you tell him to keep pushing the reset button and take a screwdriver,
put it across a high voltage transformer.

Good grief.

[BurfordTJustice]

a..
trader4 a.. posted on September 6, 2013, 10:56 pmOn Friday, September 6,
2013 6:22:19 PM UTC-4, snipped-f...@optonline.net wrote:




"Cyndi Jacobs" <cyndi...@A0L.C0M> wrote in message
news:E_FwD.509212$tK2.2...@fx42.iad...

:
:

[trader_4]

Connect a voltmeter to the AC output and see if you see 240V when it's
briefly running. The controller looks for that and if the generator
isn't generating, it shuts it down after it runs briefly, maybe 15 or
30 secs. In other words, your problem could be in the generator, not
the engine.

[BurfordTJustice]

That is not what you said in 2013 to the question..WTF??





"trader_4" <tra...@optonline.net> wrote in message
news:0360a876-9f57-49ec...@googlegroups.com...

:

[trader_4]

On Sunday, October 14, 2018 at 9:50:14 AM UTC-4, BurfordTJustice wrote:
> That is not what you said in 2013 to the question..WTF??
>

It sure is, silly Russian troll.

"Also, as I recall, the generator
control looks for normal voltage after start-up. If it doesn't
see it, then it will shut it down. "

The other info that I gave back then is also useful and the poster
should read it. BTW, what did you contribute to this AHR question
or *any* on topic AHR question? Answer: nothing

[BurfordTJustice]

a.. trader4 a.. posted on September 6, 2013, 10:22 pm

Friday, September 6, 2013 5:46:31 PM UTC-4,

snipped-f...@snyder.on.ca wrote:

Could be something simple like that. Or it could be more serious. I went
through diagnosing one last year that also started up, ran for some number
of seconds, maybe 10 - 15 secs or so, then shut off. As I recall, a few
things happen around that time. One is that upon starting, the ignition
voltage is supplied by the battery, but then after starting, it switches to
being supplied by one generator winding that serves that purpose. If that

winding or associated circuit is bad, it loses ignition. Also, as I recall,

the generator control looks for normal voltage after start-up. If it doesn't
see it, then it will shut it down.

In the generator I had, it was a bad rotor for sure, and possibly a bad
stator too. I took a look at all the complaints on Amazon about similar
Generacs and concluded it wasn't worth fixing. That had also been the
conclusion of the service guy who diagnosed it for the neighbor I got it
from. Being that it was only about 5 years old, I thought I might get lucky
and be able to fix it, but it didn't pan out.
I found the Generac service manual online which had good detail on the
various test procedures.

"trader_4" <tra...@optonline.net> wrote in message

news:23c414ba-d2e2-4419...@googlegroups.com...

[trader 0]

replying to Cyndi Jacobs, trader 0 wrote:
What oil burner??
subject is; Generac generator (natural gas) starts but won't stay running

[Fred McKenzie]

In article <vjwwD.14470$8g....@fx08.am4>,

Dave <caedfaa9ed1216d60ef...@example.com> wrote:

> replying to The Daring Dufas, Dave wrote:
> Oil light stays on and it keeps shutting down

Dave-

Before the generator's engine starts, there is no oil pressure. The oil
sensor is ignored until the engine has a chance to come up to speed. If
it then shuts down, it normally indicates a low oil level.

If you are sure there is enough oil, disconnect the wire to the oil
sensor and see if the engine keeps running. You could have a bad oil
sensor.

Fred

[lhi...@gmail.com]

As I discovered on my Generac propane powered generator, rusting internally caused a leak between the exhaust chamber and the other air chambers. After I plugged the leaks by mounting a cover plate, the generator started and continued running. Apparently the exhaust was starving the motor for oxygen.

[dannyj...@gmail.com]

If you choke out the throttle body it will run

[Michael Hovey]

On Friday, May 29, 2020 at 7:49:38 PM UTC-4, dannyj...@gmail.com wrote:
> If you choke out the throttle body it will run

yes it ran after I choke it out.

[Mike H.]

Yes I choked it out and it ran fine

--
For full context, visit https://www.homeownershub.com/maintenance/generac-generator-natural-gas-starts-but-won-t-stay-runnin-762399-.htm

[Tekkie©]

On Thu, 4 Feb 2021 14:45:03 +0000, Mike H. posted for all of us to digest...

>
> Yes I choked it out and it ran fine

From my crystal ball it sounds to me like a vacuum leak around the carb. Look
on U Tube for help on this because I think Generacs are a popular topic.

--
Tekkie

[Clare Snyder]

More likely a problem with the demand regulator - particularly if you
did any screwing around with it

[Mike H]

No screwing around with it, found a lot of rusted metal in cavity where it is . Thought some rust got in plenum or regulator.

[Mike H]

No carb, but it does have airbox and no openings i can see

[Clare Snyder]

On Sat, 6 Feb 2021 16:30:58 +0000, Mike H
<b1b6529b2eac1df5...@example.com> wrote:

>No screwing around with it, found a lot of rusted metal in cavity where it is . Thought some rust got in plenum or regulator.

How old is this thing??? What engine? Might - possibly - be worth
putting on a new fuel system - - -?

[Sterling]

My generator is a older model generac generator i think it was built in the 90s it was in storage for about 20 years or so a friend of mine had it and gave it to me . The problem i have with it is when it starts it runs for about 7 seconds then it dies each time i start it and i wondering what's the problem can you guys help me out here.

[trader_4]

First place to start, put a meter on it and see if you get correct voltage while it's running.
When it starts up it checks for voltage and if it's not correct, it shuts down. If this is a
natural gas model, that's the most likely cause.

[Marilyn Manson]

On Thursday, March 3, 2022 at 9:45:11 AM UTC-5, Sterling wrote:

> My generator is a older model generac generator i think it was built in the 90s it was in storage for about 20 years or so a friend of mine had it and gave it to me . The problem i have with it is when it starts it runs for about 7 seconds then it dies each time i start it and i wondering what's the problem can you guys help me out here.

Has it ever worked for you? You say your friend gave it to you, but I can't tell if that
is just extra info. Has it actually been 20 years since it was last started?

What kind of fuel? How was it stored? Was the fuel left in it? Have you
cleaned the carburetor?

How are you setting the choke? If it's warm out and you set/leave the
choke on full, it may stall soon after starting. (When my snowblower is
warm, I have to set the choke at halfway to start the engine but then
immediately turn off the choke to keep the engine running.)

How's the oil? Many generators will shut down if there is low oil pressure.
Champion (I know you said Generac) claims that the sensor can stick to
the bottom of the crankcase and "think" that it is low on oil. They are talking
about new units, but I could see that happening after 20 years of storage.
You could try disconnecting the sensor to see if that helps.

More details might help us help you.

[Marilyn Manson]

I've never checked the voltage of a generator within the first 7 seconds. Is that enough time for the
voltage to settle down and be considered stable?

When it's cold out, it might need more than 7 seconds before the choke could even be turned off. I
don't plug anything in until my generator is running smoothly with the choke fully off.

[Dan Espen]

Marilyn Manson <comawhit...@gmail.com> writes:

> On Thursday, March 3, 2022 at 9:45:11 AM UTC-5, Sterling wrote:
>> My generator is a older model generac generator i think it was built
>> in the 90s it was in storage for about 20 years or so a friend of
>> mine had it and gave it to me . The problem i have with it is when it
>> starts it runs for about 7 seconds then it dies each time i start it
>> and i wondering what's the problem can you guys help me out here.
>
> Has it ever worked for you? You say your friend gave it to you, but I
> can't tell if that is just extra info. Has it actually been 20 years
> since it was last started?
>
> What kind of fuel?

In the subject line, it's natural gas.

I had a natural gas pool heater. It would turn on, run for a few
minutes, then turn off. There was a safety feature, if the heater
didn't sense sufficient heat being produced, it would turn off, wait a
few minutes and try again. I had to replace the temperature sensor.

Other wild guesses: Insufficient gas flow. Old gas in the line, give it
multiple tries. Cobwebs clogging the orifices.

--
Dan Espen

[Bob F]

Insufficient supply of gas to the engine - pipes or pressure too small?

[Marilyn Manson]

On Thursday, March 3, 2022 at 2:37:29 PM UTC-5, Dan Espen wrote:
> Marilyn Manson <comawhit...@gmail.com> writes:
>
> > On Thursday, March 3, 2022 at 9:45:11 AM UTC-5, Sterling wrote:
> >> My generator is a older model generac generator i think it was built
> >> in the 90s it was in storage for about 20 years or so a friend of
> >> mine had it and gave it to me . The problem i have with it is when it
> >> starts it runs for about 7 seconds then it dies each time i start it
> >> and i wondering what's the problem can you guys help me out here.
> >
> > Has it ever worked for you? You say your friend gave it to you, but I
> > can't tell if that is just extra info. Has it actually been 20 years
> > since it was last started?
> >
> > What kind of fuel?
> In the subject line, it's natural gas.

The OP (and I therefore assume the subject line) is from 2013
from an OP named TOM.

This post is from today (3/3/2022) from Sterling. I chose not to assume
that he was asking about the same type of generator. Safer to ask and
get an answer from the person that asked the most recent question.

>
> I had a natural gas pool heater. It would turn on, run for a few
> minutes, then turn off. There was a safety feature, if the heater
> didn't sense sufficient heat being produced, it would turn off, wait a
> few minutes and try again. I had to replace the temperature sensor.
>
> Other wild guesses: Insufficient gas flow. Old gas in the line,

Old natural gas in the line? I didn't know that that was a thing. Not saying
it isn't, just never heard of it.

> give it multiple tries.

As far as multiple tries, seems like he has tried that, but granted, he doesn't
say how many times.

"it runs for about 7 seconds then it dies each time i start it"

I wonder how many 7 second tries it take to get old natural gas out of the line,
assuming it is natural gas.

> Cobwebs clogging the orifices.

That could be an issue.

[Clare Snyder]

On Thu, 03 Mar 2022 14:45:03 +0000, Sterling
<26097aa4c607b5ce...@example.com> wrote:

>My generator is a older model generac generator i think it was built in the 90s it was in storage for about 20 years or so a friend of mine had it and gave it to me . The problem i have with it is when it starts it runs for about 7 seconds then it dies each time i start it and i wondering what's the problem can you guys help me out here.

Get a gas technician out to check the regulator/converter/vaporizer
unit. For some reason it is likely not passing fuel. On a Generac heap
it could be just about anything else too - the low oil shut-down
switch is a known buggaboo on many of their products.

[Dan Espen]

I was envisioning this thing outside somewhere with a long gas line
leading too it. Yeah, probably not very likely.

>> give it multiple tries.
>
> As far as multiple tries, seems like he has tried that, but granted, he doesn't
> say how many times.
>
> "it runs for about 7 seconds then it dies each time i start it"
>
> I wonder how many 7 second tries it take to get old natural gas out of the line,
> assuming it is natural gas.
>
>> Cobwebs clogging the orifices.
>
> That could be an issue.

I have a friend with a generator that runs on propane which burns a lot
hotter than NG. Maybe this thing has a NG/Propane adjustment?

--
Dan Espen

[Jacob Jones]

It wouldn't be overheating that quickly.

[Peeler]

On Fri, 04 Mar 2022 12:49:45 +1100, Jacob Jones, better known as
cantankerous trolling senile geezer Rodent Speed, wrote:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>

--
JimK addressing senile Rodent Speed:
"I really feel the quality of your trolling has dropped in the last few
months..."
MID: <n8idndHg5972A2DD...@brightview.co.uk>

[trader_4]

My comments were in the context of a Generac natural gas generator, the thread was
titled that way, but the poster who revived this old thread didn't say what exactly it is
that they have. The Generac natural gas standby generators are the ones that will
shut down after about ten seconds if the control logic does not detect proper voltage.
I know, because I too got one for free via a neighbor. That one was only maybe five
years old. Knowing the symptom, I figured maybe it was just a bad senor,
like for oil pressure, that was the problem. I obtained the service manual online and
figured out what was going on. The generator section was not producing voltage,
causing it to shut down. Looked like it was a bad rotor, but I didn't have the right test
equipment to be able to fully check the stator. And then while looking for the cost
of parts, I found a huge number of terrible reviews on Amazon for the Generac
standby generators. Everything from them arriving new leaking oil, to firing up
regularly for the weekly test, then failing after a couple of hours when needed.
That's what happened to the one I was given. Even though it was relatively new,
the service guys told the owner it was not worth fixing, he bought another one....
So I dismantled it, sold some salvageable parts on Ebay and sent the rest to the
scrap yard.

The typical portable generators AFAIK don't have this kind of shutdown check.
Also, if they are gas powered, then you have a carb that's a prime suspect too.
With the natural gas with no carb or fuel system to foul, if it starts and quits
after ten seconds, the most likely scenario is that it's being shut down because
the voltage isn't there. Plus it's a very easy thing to check and one that most
people would not even know about.

Can't help but tell they Ebay story. One of the parts I listed was the engine, which
looked like new. Listed it for $300, for local pickup only. It was up for a month
or so and a guy in Puerto Rico contacts me and asks if I will sell it to him if he
arranges shipping and pickup. I said sure, but it's not crated, I'm not going to
figure out how to do it, etc. He says no problem and buys it. So later the shipping
company contacts me and I make sure they understand that it's not in a crate,
it's not packed. They were surprised. Some time later, they contact me again
and arrange a day and time to get it. Nobody shows up. I contact them and
they finally come, couple of guys in a van, they just haul it out and off they go.
In the process of all this I exchanged emails with the buyer, in the end he tells
me that while he was quoted like $300 to ship it from NJ to Puerto Rico, they
actually changed that to $700 and that was before they picked it up.
That didn't exactly surprise me. I told him you should have just told me that
and I would have given you a refund. He said he's a
man of his word, so he went through with it. If it was me on the other side,
I would have offered the seller $50 or so for their trouble if they would cancel
the sale.

The other thing, you would think with these generators failing all over the
place that it would not be too hard to find an engine from a local dealer
in PR instead of getting one from here. This was about a year before the
big hurricane down there. I hope he got it and it worked for him through
that, in which case I guess it makes it a lot better.

[Denny]

It'll start then flashes over speed

[Ronfox]

My generator does exactly the same thing. Generac same model

[Chester Oakley]

Is it single phase or two phase?

[Dean Hoffman]

I learned something again accidentally. There is some literal two phase left in the United States.
<https://ctlsys.com/support/two-phase_electrical_service/>
It's obsolete and might not be changed out. Some commentary and pictures
from Mike Holt's forum.
<https://forums.mikeholt.com/threads/two-phase-power.125644/>

[hub...@ccanoemail.com]

I worked at a 25 Hz. station in my youth - Ontario Power GS -
right at the foot of The Falls :

https://www.lifebynumbers.ca/history/the-rise-and-fall-of-25-cycle-hz-electricity-in-ontario/

25 Hz. was finally completely phased out - in the late 1980's
.. if I remember ..
John T.