Onan

[rldavis]

I have an Onan Microlite 2.8KV that starts and runs for about 20 minutes then dies but immediately restarts. It will run for about 5-10 minutes and die again. This is the sequence.
I have replaced the plug, fuel filter, fuel pump, air filter, and changed the oil (reading full) charged the battery, cleaned all connections, and connected the fuel to a separate fuel source. It starts and runs under full load with no surging or smoking - but dies after 20 minutes.
I am thinking coil? voltage regulator? control board?
Any suggestions?
thanks,
Robert Davis

[Handbasket]

If you haven't already, and have the factory resistance values for the coil, run it 'til it gets hot and quits, then meter it asap.

It may still be the VR, I _think_. The 2800 gets the voltage to make spark from the battery when cranking, but when the switch is released, it has to self-generate the spark. So the VR has be functioning for it to keep running. I didn't bother to check mine for spark before replacing the VR, but doubt it had any.

You really should take J-D's suggestion and ask the mod to move this to the tech forum.

Jim, "The nicest thing about the future is that it always starts tomorrow."

[rldavis]

Hello everyone.
I am the guy with the microlite 2.8 that starts and dies. I pulled the coil and the primary read 0.8 ohms and the secondary 1,150 ohms. There is a test for the voltage regulator but it requires a diode test meter. I installed an inline spark checker and the set starts with spark, the spark meter light dies and the engine dies. Does this sound like a bad coil or a bad voltage regulator? I can take the voltage regulator to cummins for testing but they are rude and often do not want to help you - especially if you are a do it your self type.
THanks,
Robert Davis

[Handbasket]

On my '06 vintage 2800 Microlite (sorry, don't recall the spec letter, not going to the trouble of finding it), the voltage regulator is changeable, awkwardly, with the generator in the vehicle. It will give your symptoms when it fails. BTDT.

I had replaced the fuel pump a few months before. When I started having issues again, I found the filter and fuel line full. The VR was the next logical suspect.

The VR is a flat potted component, maybe 1/2 the size of a pack of ciggies. It can be felt but hardly seen via the access door under the engine. It's at the end of the white wire bundle, bottom center in this pic:Feel around in the base pan under the valve cover. I think the cost was about $220 (?) from Flight Systems. I think they have some troubleshooting stuff on their website.

IIRC, the hot ticket for removing it is a 1/4" ratchet and a #25(?) Torx bit. Just one Torx screw, and the big wire plug. The very fiddley/frustrating part is getting the dam' screw back into the hole by feel. There's no locating tab, or lead-in for the hole; just a flat surface with a tapped hole that you have to find thru the VR.

Jim, "About one drink away from telling everyone hat I really think."

[j-d]

Here's some info the OP sent me:

###This is the most frustrating thing I have seen. I am going to test the coil today and there is also a test for the voltage regulator. I am not sure about the control board.
The Model Number is 2.8KVFA26100K Spec K Serial - G040668830
Do you know if there is any way to test the Control Panel? It seems to run find but something is getting hot and shutting the system down. Also, I have had people comment on the low oil sensor switch mounted in the oil pan. Whew! What a pain in the neck.###

On every modification, ONAN increments the Spec Code. We have the 4KY and it's also up to Spec "K." In the case of the 4KY, that Oil Sensor had been discontinued by the time they got to "K" which illustrates why the hard core genny guys want the Spec. No need to chase a feature that isn't there anymore. Or ignore a new or modified feature.

OP - you may want to click "notify moderator" and ask it to be moved to Tech Issues. Several genny guys hang out there.

[j-d]

Thanks for pointing out the new pump. Hard to tell Who's Who and What's What since sometimes there are different threads on different forums.

For somebody who's really into gensets to help effectively we'll need to know the Spec. For example, no point in considering an oil sensor that a Series started out with that was discontinued by the time an OP's Spec was produced.

They can also probably suggest alternative components, like Dinosaur or Flight Systems, for electrical parts.

[rvten]

The OP already changed the fuel pump.
Could be the control board. Sure hope not. That is a $300+ item.

I had same problem as you. Mine turned out to be the fuel pump.

[j-d]

Suggest you add the "SPEC CODE" and then ask Moderator to move it to Tech Issues. The genset guys tend to hang out over there.

A couple of us have had fuel pump failures on the KV series ONAN. Those are the KV's 4KW big brothers. The genset would run awhile then quit.

Please don't run out now and buy a fuel pump. It may come to that but please let the guys weigh in on your problem.