JD 322 ignition module testing

[angelugs]

I'll start troubleshooting from square one tomorrow. Had to get my mowing done and take a break from the 322. As far as answers to your questions radios1, everything seemed to check out up to testing the ignition module. I THOUGHT I was reading the chart shown in the service manual correctly but evidently not. If your curious about a wiring diagram there's one available online. Just Google "jd322 ignition wiring diagram" and you'll see it. I'm just focusing on the pulsars, ignition module, plugs/wires and coils for now.

Thanks for your interest in my problem.

 

[radios1]

I'm getting a strong feeling there's a corroded or loose connection between the ignition module and the coil..(check that) but I'll check for the wiring diagram.. I found the wiring diagram, and found you have 3 "pulsars" one for each coil. in this case, it may be one of those causing the problem, as everything you did so far narrows it down greatly. the ignition module you said you tried a new one, so that's not it, and you said you swapped the coils, that's not it either.

 

[angelugs]

This evening I started the troubleshooting process again. Everything electrical checked out. Took a minute and thought about everything I'd done to this point and the results I got. Starting to think it could be low compression in the cylinder I've never seen fire since starting the process. Dug out my OLD compression tester and found the rubber end split/brittle and the valve core wouldn't hold pressure anymore. I tried checking pressures anyway and it looks like the suspicious cylinder is only getting around 70 - 80lbs. compression. Checked another and it looked closer to 100lbs. Specs. call for 113lbs. minimum and 14lbs. variance. I'll have to run down another tester somewhere so I can feel confident in the readings. I'll check for continuity on the positive wire for the dead cylinder from it's coil back to the ignition module too.

If it needs valves or rings that will be outside of my DIY capabilities. Got any idea what a engine rebuild would cost?

 

[radios1]

This evening I started the troubleshooting process again. Everything electrical checked out. Took a minute and thought about everything I'd done to this point and the results I got. Starting to think it could be low compression in the cylinder I've never seen fire since starting the process. Dug out my OLD compression tester and found the rubber end split/brittle and the valve core wouldn't hold pressure anymore. I tried checking pressures anyway and it looks like the suspicious cylinder is only getting around 70 - 80lbs. compression. Checked another and it looked closer to 100lbs. Specs. call for 113lbs. minimum and 14lbs. variance. I'll have to run down another tester somewhere so I can feel confident in the readings. I'll check for continuity on the positive wire for the dead cylinder from it's coil back to the ignition module too.

If it needs valves or rings that will be outside of my DIY capabilities. Got any idea what a engine rebuild would cost?

a rebuild kit here ENGINE COMPLETE REBUILD KIT - READ DESCRIPTION!: Yanmar Tractor Parts is $656.65 that's do it yourself, parts only, they don't mention if the pistons and rings are oversize, which may be needed, maybe you ask what you want, so, if someone has this done at a shop, labor has to be figured in.. maybe someone else has a better estimate on having it rebuilt. there is also the possibility of a repower,(different type of engine) this make(yanmar) seems pricey for parts.. OH, check your valve lash first!..

 

[angelugs]

Compression on all cylinders checked out good. With that being said, I don't see how my problem can be mechanical unless the pulsar for one cylinder has come loose from the block and is dangling inside the flywheel housing. I'm not ready to "dig that hole" yet.

Haven't check the valve clearances but can't see that causing the misfire with the compression reading I got from the "dead" cylinder.

Now what?

 

[radios1]

Compression on all cylinders checked out good. With that being said, I don't see how my problem can be mechanical unless the pulsar for one cylinder has come loose from the block and is dangling inside the flywheel housing. I'm not ready to "dig that hole" yet.

Haven't check the valve clearances but can't see that causing the misfire with the compression reading I got from the "dead" cylinder.

Now what?

with your updated info, you don't have a mechanical problem, the problem must be the ignition module is not getting the pulse from the "pulsar" to fire that one cylinder.. bad "pulsar".. you have checked everything else.. that cylinder will NOT fire without a spark..

 

[angelugs]

Checked pulsar on bad cylinder again today per tech manual procedure even though I've done it a half dozen times before. According to the test the pulsar is working as it should. Compared the brightness of the blinking test light on the bad cylinder to what it looked like on a firing cylinder and it looked the same. That's the only test the manual gives for the pulsar. As I understand it the only thing the pulsar does is break the low voltage circuit which in turn causes the high voltage to be created for the spark plug. Checked the coil again and, per manual, it tests fine. Other than resistance values there's no other indicators for a bad coil. I'd have A LOT of tearing down to do to get to the pulsars and since they're checking out okay I don't think that's where the problem lies. Having said that, with this type of ignition system there's not that many places to look for a problem and I think I've looked at them all. Hate to think I'm at the point of trial and error till I purchase and replace the right part.

 

[radios1]

Checked pulsar on bad cylinder again today per tech manual procedure even though I've done it a half dozen times before. According to the test the pulsar is working as it should. Compared the brightness of the blinking test light on the bad cylinder to what it looked like on a firing cylinder and it looked the same. That's the only test the manual gives for the pulsar. As I understand it the only thing the pulsar does is break the low voltage circuit which in turn causes the high voltage to be created for the spark plug. Checked the coil again and, per manual, it tests fine. Other than resistance values there's no other indicators for a bad coil. I'd have A LOT of tearing down to do to get to the pulsars and since they're checking out okay I don't think that's where the problem lies. Having said that, with this type of ignition system there's not that many places to look for a problem and I think I've looked at them all. Hate to think I'm at the point of trial and error till I purchase and replace the right part.

FIRST, check for a corroded or loose connection between the ignition module and the coil!.. what you should do, is put a voltmeter across the primary coil wires, and crank the engine, if the meter don't jump when cranking, then a "pulsar" is bad, despite the other tests. the "pulsar" needs to send a strong enough signal, and at the proper voltage levels to trigger the ignition module, which sends a pulsed signal to the coil, which creates the spark.. one of these tests are fooling you!.. something has to be bad.. if you had a means of switching the "pulsar" signal from on cylinder to another, and checked for spark, and you got a spark on the plug, then you know it's a bad pulsar!..

 

[angelugs]

After fighting this problem for the better part of a month I finally figured it out. Turned out I had a bad ignition coil. What took me so long to fix it was the bad coil still checked out with the tech manual specs. every time I put a meter on it. After going through the entire troubleshooting procedures listed in the manual NUMEROUS times I finally decided I had to start replacing parts until I found the problem. Since I'd already purchased an ignition module and it wasn't the problem I decided to go with a new ignition coil next. I know a coil is more expensive than a pulsar but I wasn't looking forward to removing all the parts necessary to get to the pulsar so I went with the coil.

So in summary I'd say I learned one thing and was reminded of another: Don't believe EVERYTHING you read in a tech manual .... and when having to purchase parts to find the problem, don't start with the most expensive part.

I want to thank everyone who tried to help me get my 322 running smooth again.

By the way, I still have the BRAND NEW unused JD ignition module (AM876024) I'll sell for less than you'll get one from a dealer.

 

[radios1]

After fighting this problem for the better part of a month I finally figured it out. Turned out I had a bad ignition coil. What took me so long to fix it was the bad coil still checked out with the tech manual specs. every time I put a meter on it. After going through the entire troubleshooting procedures listed in the manual NUMEROUS times I finally decided I had to start replacing parts until I found the problem. Since I'd already purchased an ignition module and it wasn't the problem I decided to go with a new ignition coil next. I know a coil is more expensive than a pulsar but I wasn't looking forward to removing all the parts necessary to get to the pulsar so I went with the coil.

So in summary I'd say I learned one thing and was reminded of another: Don't believe EVERYTHING you read in a tech manual .... and when having to purchase parts to find the problem, don't start with the most expensive part.

I want to thank everyone who tried to help me get my 322 running smooth again.

By the way, I still have the BRAND NEW unused JD ignition module (AM876024) I'll sell for less than you'll get one from a dealer.

how is that possible though, you said you swapped coils, and still didn't get a spark to that cylinder.:confused2: