Onan P218 cranks no fire

Genz · Mar 30, 2019

All: Got a Onan P218 that will crank but no fire, at a loss and need help figuring this out. I have replaced the Trigger Ring, Ignition module, Coil, condenser, Plugs and wires. I do have fire now, but very very weak. I have jump the low oil pressure switch to by- pass or eliminate that for now. Battery is good....I suppose its possible I have bad new parts? The module shows battery voltage on part of the revolution then falls to 1-1.5 volts the rest of the revolution, just as the manual states it should. Connections are all cleaned, including battery ground to engine ground. Would appreciate any input you might have. Oh, when switch is on, there is battery voltage on + side of coil.

Bob · Mar 30, 2019

Do you have the coil and module wired up just like this diagram?

Note the condenser is for ignition "noise" suppression only and goes to the (+) side of the coil.

<img src = "https://i.imgur.com/sLUbGPL.jpg">

Genz · Mar 30, 2019

Yes, I believe I do. Red lead from Module, condenser, and the white wire all live on + side of coil. The only wire that lives on the - side of coil is the black lead from Ignition Module

T.R.K. · Mar 30, 2019

By any chance do you have BOTH of the sparkplug wires off the plugs? That was screwing me up once. That time I never saw a spark until I
put the other plug wire on the plug.

By any chance are your spark plug wires in really good shape? That was the problem at another time. One wire was burnt off back about 3/4"
inside the insulation. (I told my boss that wire was a problem about a year before when we overhauled it: He said to leave it on since it
was running at that time.)

Do you have your 12v supply to the SMALL post on the coil? The other wire from the pickup goes on the large post on the coil.

Genz · Apr 3, 2019

Thank you to all that replied: Even tho I have weak fire, I went ahead and put this thing back together. Lo and behold it runs like a champ. I would have never thought so, but it must be the way its suppose to be... We'll see what the future holds when we start giving this thing a work-out....thanks again!

Bob · Apr 3, 2019

(quoted from post at 10:29:06 04/03/19) Thank you to all that replied: Even tho I have weak fire, I went ahead and put this thing back together. Lo and behold it runs like a champ. I would have never thought so, but it must be the way its suppose to be... We'll see what the future holds when we start giving this thing a work-out....thanks again!

Genz, thanks for letting us know, it may help someone else in the future who finds this thread in the archives.

SO many come for help and NEVER are heard from again.

Onan P218 cranks no fire

Genz

Member

Bob

Well-known Member

Genz

Member

T.R.K.

Well-known Member

Genz

Member

Bob

Well-known Member

Similar threads