Onan 10k diesel Cranks but will not start ...Help

[kerryvan]

Index of /~n0nas/manuals/onan

these may have the info you are looking for.

kerry

[steve11669]

I would put a new fuel pump on. $90.

[jerichorick]

Originally Posted by RobRoy

Onan 10k Generator cranks over but will not start and run or even attempt to fire a cylinder for that matter.

It has been running fine has about 400 hours on it and had a full service in it 3 months ago and was ran as recently as two weeks ago and started and ran just fine.

Coach has ¾ Fuel tank of fuel and the coach fires right up, so I know the fuel is good.

Ambient air temp trying to start has been @ 34f

Tried starting the genny with coach running and coach not running, still cranks fine but will not fire a cylinder or start.

When I hold the genny start button down to start and I can hear what I believe to be is the fuel pump running and the light flashing and get a 30 second delay before it starts cranking so I assume the glow plugs are warming up also ( key word assuming)

I have also tried holding the start button down to the bottom side also for a minute, then tried starting …makes no difference.

I see no flashing diagnostic lights on any of the start buttons in the coach or on the genny itself and have also tried starting it from all 3 locations and it makes no difference cranks but no start same scenario .

Im looking for some advice and some direction.

I have done some searching but am struggling to find something that leads me down a diagnostic path.

I was also googling for a trouble shooting manual and seemed to come up empty.

Any and all help appreciated

10hdcaa11506a

Attachment 149280

I can think of 2 possible problems off the top of my head. One: Pull the connector apart that goes into the controller. Mine is located at the front left of the gen-set. The other thought is a bad sensor on the engine. I think I did get the Onan handbook PDF to attach. I hope this helps.

Rick Y

[RobRoy]

Originally Posted by kerryvan

Index of /~n0nas/manuals/onan

these may have the info you are looking for.

kerry

Thank you, I will take a look

[Twomed]

Originally Posted by steve11669

I would put a new fuel pump on. $90.

AIRTEX E11020 on Amazon $38

[RobRoy]

Day two of Onan 10k diesel no start saga and gonna be a long one. I have to help make funeral arrangements for a friend who died suddenly so I will be sidetracked from this project for a bit. So if I don’t respond promptly you will know why.

So this morning, after walking the dogs and I had a couple of minutes and decided to try to start the generator.

38f Deg ambient air this morning

I hold the start button at the genny in the down position for one minute and when doing so I believe I hear what is the fuel pump running.

Then hold the start switch in the upper position and when doing so hear a click from the genny engine area and the light flashes on the start switch for about 30 seconds and then the genny start to crank and the cranking RPM seems to be normal.

After cranking for for 15-30 seconds?..... nothing not even a hint as to making an attempt to fire off……. as stated earlier, I have the genny rolled out the front of the coach and working from there when I noticed white smoke while cranking from the exhaust and a pretty good amount and tried this more than once to verify what I was seeing ...and yep white smoke while cranking.

So I ass-u-me ing that the white smoke if from fuel ?….and it must be getting fuel?

So at first I'm thinking glow plugs?

As I think about it and thinking that maybe glow plugs or what controls them are the issue? it doesn’t even think about firing….nothing

So before I leave the barn I go over my old 7.3 International crew cab dually that has been sitting for 4 months and pull off the winter covers and [Mod Edit] unplug the glow plug controller crank it over and it fires off like it was running 10 min ago.

Over the years I seem to remember being around diesel's that had pre-heater issues, be it glow plugs or grid heater of whatever? when they failed in cold climates what I seem to remember was that they would at least try to fire maybe stumbing misfiring maybe even not start but you would at least seem to hear something when trying to fire it up ........ I hear nothing from my genny..but I do see white smoke.

I’m trying to give all the details because we are supposed to leave for Fla soon and with everything else now going on ....my frustration level meter is pegged.

Thanks again

[YC1]

Your patience will be rewarded. And Florida is nice and warm right now so come on down.

Did you check those fuses out? I could have overlooked your response.

[twinboat]

Originally Posted by RobRoy

Day two of Onan 10k diesel no start saga and gonna be a long one. I have to help make funeral arrangements for a friend who died suddenly so I will be sidetracked from this project for a bit. So if I don’t respond promptly you will know why.

So this morning, after walking the dogs and I had a couple of minutes and decided to try to start the generator.

38f Deg ambient air this morning

I hold the start button at the genny in the down position for one minute and when doing so I believe I hear what is the fuel pump running.

Then hold the start switch in the upper position and when doing so hear a click from the genny engine area and the light flashes on the start switch for about 30 seconds and then the genny start to crank and the cranking RPM seems to be normal.

After cranking for for 15-30 seconds?..... nothing not even a hint as to making an attempt to fire off……. as stated earlier, I have the genny rolled out the front of the coach and working from there when I noticed white smoke while cranking from the exhaust and a pretty good amount and tried this more than once to verify what I was seeing ...and yep white smoke while cranking.

So I ass-u-me ing that the white smoke if from fuel ?….and it must be getting fuel?

So at first I'm thinking glow plugs?

As I think about it and thinking that maybe glow plugs or what controls them are the issue? it doesn’t even think about firing….nothing

So before I leave the barn I go over my old 7.3 International crew cab dually that has been sitting for 4 months and pull off the winter covers and just for shits and grins unplug the glow plug controller crank it over and it fires off like it was running 10 min ago.

Over the years I seem to remember being around diesel's that had pre-heater issues, be it glow plugs or grid heater of whatever? when they failed in cold climates what I seem to remember was that they would at least try to fire maybe stumbing misfiring maybe even not start but you would at least seem to hear something when trying to fire it up ........ I hear nothing from my genny..but I do see white smoke.

I’m trying to give all the details because we are supposed to leave for Fla soon and with everything else now going on ....my frustration level meter is pegged.

Thanks again

Make sure, that if you have a pre-heater, it's working.

I have an old Volvo Penta marine engine with pre-combustion chamber heads. If I don't pre-heat, it won't start. That's in warm weather !

[RobRoy]

Day 2.

Chapter 2.

Pulled the panel above the start switch on the genny itself to check the fuses and both fuses looked good and checked good with and ohm meter and they both have power at both side of the fuses.

So then I have a brain storm.

Because of seeing the smoke from the exhaust while cranking and no start I decided to remove the air filter and put my heat gun up inside the intake hose and give it a try thinking it has something to do with glow plugs and preheat ....................Nothing! still cranks over but no start, not even a bit of anything indicating it's trying to fire up..other than white puffs of smoke.

[RobRoy]

Originally Posted by twinboat

Make sure, that if you have a pre-heater, it's working.

I have an old Volvo Penta marine engine with pre-combustion chamber heads. If I don't pre-heat, it won't start. That's in warm weather !

Pulled the air filter put a heat gun in the intake hose ( not a hair dryer) and still nothing even with 38f ambient air

[RobRoy]

Originally Posted by YC1

Your patience will be rewarded. And Florida is nice and warm right now so come on down.

Did you check those fuses out? I could have overlooked your response.

The two fuse under that panel check good, voltage present both in and out.

[kerryvan]

The one symptom that is troubling for me, is the puffs of white smoke. I thought white smoke only came from water vapor, not from diesel. I could be very wrong or lost my memory,, (I'm still looking as I type)..

kerry

[xydial]

Not an expert on diesel engines, but I do know that white smoke is unburnt diesel fuel!

Sounds like glow plugs.

[twinboat]

Originally Posted by xydial

Not an expert on diesel engines, but I do know that white smoke is unburnt diesel fuel!

Sounds like glow plugs.

Agree, but it may not be enough to fire. There should be dark gray to black smoke, if its trying to run.

If mine, I would pull the air filter out and mist the intake with WD40.