Onan p220 shuts off sporadically

[2000pstrokeblue 1]

Hello brand new to site but looking to fix a problem and it seems like there are a lot of guys here who deal with the Oman p220. So here goes I have onan p220g in a Miller welder/generator. Been trying to fix it for quite some time in and off and now I just need to get it done. Originally it would start and run for 5-10 mins then quit like you just shut the switch off, when this would happen and you tried to restart it with an inline spark plug tester you would have no spark, if you waited a half hour or so it would start back up and repeat said problem. I replaced the coil and it did not improve. After some research and advice I bypassed the oil pressure switch and now it will run anywhere from 1-10 mins and restart immediately after dying. If you watch the inline spark tester it will be nice and bright then fade sometimes and die or stutter a little and brighten back up and continue to run. The motor serial # is g903711949.  Now I was told the voltage regulator is the little gray box above the oil filter with 3 wires and to check that, and to check  the ignition control module behind the flywheel that is the trigger for the spark signal, the last 2 I haven't checked yet and am looking for the process any thought or help would be Greatly appreciated 

Edited April 23, 2016 by 2000pstrokeblue

[boomers_influence 106]

2000

please e/mail me.

boomers_influence@yahoo.com

i will send you pages 8-1 and 8-2  from the P service manual.

this will helps you with these tests.

thank you. boomer ( the used onan engine parts guy,also NOS and new )

[DougC 2,643]

Hello and to the forum. boomer will get you all fixed up.   

[tbarnhart 240]

Check out the sticky thread at the top of the Wheel Horse Electrical section. I think the information is there to do a pretty good diagnostic.

[2000pstrokeblue 1]

So I got an hour to play with it today... It does not lose power to the coil when it .     Loses spark, it has 13.8 volts across the battery when running, and when you do the test with the negative lead of the multimeter on the negative battery post and the positive lead on the negative post of the coil and rotate the flywheel by hand it switches from battery voltage to 1.4 when cold, immediately after it quits running it switches from battery voltage to 2.6, I pulled the condenser to check for a part # and can,t find one, I will be rechecking the coils resistances in the near future

[boomers_influence 106]

2000

the condenser ( 312-0256 ) is NOT needed to run / test the engine.

you can redo the test with out the condenser,

but your module does not pass the test in my opinion.

when testing the coil, it MUST be unhooked ,

for proper readings.

thank you. boomer

[2000pstrokeblue 1]

So my "new" coil so far has been tested "hot" after running across the plugs read 21.6 in the 200k range and the 2 smaller terminals test 3.6 in the 200 range also hot,  and the same cold, the "old" coil test 16.8 and 3.5 cold in the same ranges and 18.8 and 3.6 hot. Both coils were off the machine,The condenser seems relatively cheap to replace is there a way to test it tho? When you say module are you referring to the ignition module? Do you happen to know that part # as well? And if my understanding is correct that is behind the flywheel and its paired with some kind of trigger ring? Thanks boomer I think it's getting close to narrowed down now

[tomshorse4keeps 7]

Not sure about the electrical, on a Miller welder, but my 520H was doing the same thing, would just shut off, no power at all, nothing! Ten minutes later, it would start up, like it never happened! Thanks to my gracious Toro dealer, who is not selfish, with his 40+ years of knowledge. He doesn't always, have to make money off you, with service work. He told me, there is a nine pin, two part, plastic electrical connector, male to female, the color of mine is white. It is fastened, to the top steel rail, of the battery box, with a cable tie. This connector "shorts out" to the steel rail, unfortunately you may not be able to see this, unless you, separate "unplug" the two parts. Mine looked fine, until I took it apart. Then I was able to see, a couple of the pins were "fried". I found part numbers, for the two part male to female connector, on Toro's website and was able, to order from Toro dealer, their only a couple bucks, but may take some time, to receive them. Radio Shack makes a little tool, to remove the pins, from the plastic connector, looks and operates, similar to a hyperdermic needle, but its made of metal. Use wire markers, when you remove pins,  you MUST put them back together, EXACTLY the way you took them apart, unless you want, to incur major electric problems, new wire harnesses are expensive and may not be available. Toro and Radio Shack also sell the metal pins, if there burnt to bad, you can cut them off and crimp on new ones. Lastly, I took that, top steel rail off and slid a piece, of heater hose over it and reinstalled it, so it doesn't short out again. I hope this helps you, trial and error, can be expensive, and depressing.

[Lost Pup 172]

Do a search here for "Molex" connector.  A thread or two exists to show you how it done. 

 

I replaced the fuse box and the 9 pin molex connector on my 416H and my 418A . Both showed signs of burn out from shorted connections. There was/is enough wire in the harness to just cut he wires , add new ends and reconnect. I have some pics that i will post later.

Machines are rock solid dependable now.

 

[2000pstrokeblue 1]

I checked the molex connector already looked good, but I did clean it and dialectic greased it just for good measure anyway, I'm really leaning towards the ignition module and trigger ring based on te readings I got from it, just hesitant to order 1 considering their 130 + bucks

Edited April 26, 2016 by 2000pstrokeblue

[WVHillbilly520H 10,376]

The ignition module went out on my 520 about 6-7 yrs ago, it would run "fine" for 5-10 minutes mowing then rev down backfire/pop to a stop then wait 5+ minutes later fire up repeat, so I changed the coil,condenser, spark plugs, again same symptoms, finally broke down to took it to my tech guy and yep the ignition module and trigger ring was bad,and of course parts plus labor $$$ anyways that was around 600 hrs and I keep in a shed a try to maintain it properly anyways just my experiences,Jeff.

[boomers_influence 106]

2000

the coil needs to be tested by ITSELF,

not across the plugs as you state.

the new style of coil does have a higher secondary reading.

the 3 new ones i have tested are about 20,600 ohms.

i DO stock the modules, NEW and used ( tested )

and the same with the rotors.

thank you. boomer

[2000pstrokeblue 1]

I meant across the coil leads for the spark plugs, I do have it off the machine for testing purposes, boomer what does a module and ring run from you? New / used? You can e-mail me prices at firemedic6640@live.com if your more comfortable with that