318 Ignition problems

[bherr]

My '92 318 (original owner) doesn't want to run. Earlier this spring it wouldn't start - no spark. I checked the coil and control module with a VOM and they were fine so I replaced the condenser. No luck.

The chief mechanic at one of my clients suggested I test the ignition switch, I did and after I replaced it the tractor started immediately. That was about a month ago. Well now it flat out won't run.

Starter cranks, fuel is going to carb, no spark. Tested the coil and both sides check ok. When testing the control module (red lead to coil -, black lead to engine ground, jumper from battery + to coil +) the voltage stays at battery voltage; it doesn't swing between 1 volt and 12 as I turn the flywheel by hand.

Question 1: does this mean the control module is bad?
Question 2: does the engine have be pulled to replace the module?

Thanks

 

[C-Range]

I'll assume you have a P218G (electronic ignition).

I can't be of too much help with electrical advice, but if by 'module' you mean the impulse module that tells the plugs when to fire, then yes you have to pull the engine. Not only do you have to pull the motor out of the tractor, but you then have to pull the flywheel and stator off of the back of the motor. As far as I know, it's not usually the module that goes, it's the little magnetic ring that rides on the crankshaft that tells the module when to fire that goes.

The good news is that pulling a 318 motor is really no big deal. I had mine in and out routinely trying to diagnose an engine problem (long story). Pulling the flywheel off is frightening but as long as you get the right wheel puller, it's doable. The stator comes off with three screws.

One of the hurdles I found with the 318 was that since the motor is an Onan and the tractor is a JD, the tech manual for one is useless for the other so you wind up having to get both and flip back and forth between them with a little interpretation here and there.

If all else fails, (see photo)

 

[bherr]

Ensoll,
Looking at the engine - you're right, P218G - it doesn't seem all that difficult to extract. Is the easiest way to free it from the driveshaft to simply remove the 4 bolts ahead of the U-joint?
Ahhh - puller for the flywheel; I wondered about that. Is the best way to do that to use a long bar with a center screw and 2 arms that reach down to grab the outer rim of the flywheel?
The stator usually fails? I thought it was simply a ring that held a captive magnet. What's to wear out or fail?
Nice 318 replacement on the truck, but the majority of the hours on our 318 are there because my wife is convinced she does a better job mowing and that's what she's comfortable on. Who can argue with that?

 

[C-Range]

The book says to remove the 4 screws from the driveshaft/flywheel interface and pluck the engine. I did that a couple of times and eventually found it better to leave the driveshaft on the engine and pull the whole mess out together. The drive shaft will just come off of its splines. I don't understand why the book doesn't say this too since it is impossible to torque the 4 screws upon reinstallation.

For a flywheel puller, you need a flat bar type of puller. There are two threaded holes in the flywheel that you screw the puller into and then jack against the crankshaft with the center screw. You can get them at auto parts stores.

And no, I didn't say the stator usually fails, though they do fail. What I said fails is the magnetic ring that pulses the ignition module, which is behind the flywheel and stator. I don't know what would make it fail but maybe heat from the engine. I'm just stating what I've heard.

 

[bherr]

Got it. A friend dropped off an engine hoist and I'll do as you suggest to pull the whole unit. Do you know offhand what the torque spec for the 4 screws is?

You can tell I don't have the book(s) and haven't got the engine out. Looking at the parts cut that I downloaded from JD I think you're describing the rotor. I already have a new control module, so I might as well replace the rotor while everything's out.

I really appreciate your help with this.

Bill

 

[C-Range]

Sorry, but all of my manuals went with the tractor when I sold it. You can get them on eBay but be careful. There are lots of degenerates selling crap on there. I bought one manual one time and got a photocopy of a photocopy of a photocopy (no exaggeration). The images were purely black and white by this point, aka useless. And then the gremlin wouldn't return my money. Even worse, he just sold me a few chapters out of the manual, not even the whole thing and his description didn't make that clear. People like that have made me stay away from eBay as much as possible. Unfortunately, sometimes there's no place else to go. So, be careful. Whatever you do, get something somewhere. Don't fudge the torque settings if this is your machine that you've owned since new. Do it right!!!