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My 322 JD Yanmar Only runs when it wants to

9K views 25 replies 9 participants last post by  ajcan 
#1 ·
My 322 JD Yanmar Only runs when it wants to. From the reading that I have done It sounded like the Timing delay module was overheating so I did the Ebay thing got a different one and installed it. It ran for about 30 min. and stopped just as it had done before. Next I took the Timing delay module off a running 318 that I have and installed it and I got the same results. Where should I look next to solve this problem?
 
#2 ·
Assuming that it is losing it's spark, I would put a test light on the negative contact of the ignition coil. If it flashes when cranking then it is a coil problem, if not, then it has a primary control problem. If it is the latter situation, I would have to get into a wiring diagram to be of help.
 
#5 ·
John,
Are you sure you have no spark or could you have a fuel related problem. For example the fuel pump or the solenoid on the carburetor. It could be a connection to the solenoid which shuts off fuel when you turn off the key switch.

BTW, I had two 322 tractors and sold one a couple years ago. I often kick myself for selling it.
 
#7 ·
Mark Ayotte
I ran the 322 this evening till it quit then checked with a test light.
The + side of the coil lights up as soon as the key is turned on and does not flicker.
Test light on the - side wavers but does not give a distinctive break in the light as the starter is turned over. And for extra measure I unpluged the TDM and plugged in the original TDM. It still did not fire.
 
#8 ·
John,
It may seem to not have a distinctive on/off because it happens fast enough that the filament of the test light doesn't stop glowing before it's back under power. Wavering means that the primary control is trying to make and break the ground to the coil. To be positive that we aren't barking up the wrong tree, I would put a known good spark plug on the end of one of the plug wires, ground it to the engine and see if it fires when cranked over. If it fires then you don't have an ignition problem. If there is no spark, leave the key on and touch a grounded test light repeatedly to the negative post on the coil that goes to your "test" spark plug. If the coil is good, it should fire the plug every time you touch it. I would anticipate that the coil is ok, as there are three of them and,while nothing is impossible, the likelihood of all three of them being bad is slim to none. That time delay module that you are talking about controls the positive side of the coils and you have seen that the coils have power when it won't start, so that module has been ruled out. I think I'll stop there until we confirm whether it is an electrical or a fuel problem. If it continues to be electrical I'm thinking either the transistor module or it's ground supply. To be continued!
 
#10 ·
John,
I believe you have possibly eliminated a few items just by checking the +12V on the coil. This includes the ignition switch through the fuse, safety switches through the time delay control module and wires to the coils.

Mark has given you good suggestions for testing spark.

Open items:
Pulsars - Unlikely all three.
Transistor Module - Certainly possible.
Ground wire: Possible
Connector: Possible
Coils: I agree with Mark. These do fail, but all three would be unlikely.


Fuel:
Gas cap vent plugged - Loosen cap after it dies.
Fuel filter - Probably not, but worth checking.
Fuel pump - Failing or wiring.
Bad pickup hose - collapsed or leaking in air.
Carburetor solenoid - This shuts off fuel at the carb main jet when key switch turned off.
 
#11 ·
Ok I have been out of town for a short.
Every connection that I can see has a splash of dielectric grease.
I replaced the fuel filter with one that I can see through.
I have ruled out the DTM.
In my mind The fuel thing is making me wonder. The other day the gage was at 1/4 but the fuel filter was not filling up as it had before.
I have not had the time to mess. And we are going out of town in the am. + it has been cold here BRRR.
 
#13 ·
I know this thread is a year old, but I was wondering if you solved this issue. I am having the same issue with my 322. I get power on the + side of the coils (until an interlock is broken) which I think rules out the TDM. The negative side of the coils seem to have issues, I get strong pulses when the tractor decides to run, but then it will shut off for no reason. When it shuts off, no more pulses on the negative side. Is this a bad transistor module? All connections have been checked and greased, I am out of ideas!
 
#14 ·
no more pulses could indicate a transistor module or something before it
 
#15 ·
I double checked that the transistor module had ground and power even when there were no - pulses at the coils. And, since it's 'all or nothing' I assume that it can't be all 3 pulsars failing in unison. But I want to double check here because that is an expensive module!
 
#16 ·
Surprised that this thread never had the wiring diagram excerpts posted to it to help make the discussions much less ambiguous -- so here goes.


Your earlier substitution of known good TDCM units clearly rules that out, but you could have also done so by measuring the voltage at the pink wire on X18 or the + terminal on a coil to confirm that voltage is present when the key is in the RUN position. Is this voltage also present when the engine stops running after a half hour of use? If yes, then the issue is in the transistor module or the coils or pulsars. If the voltage is not present, most likely something is intermittent in the safety seat switch, the power coming from the fuses (holders or the fuses them selves...) Verify all ground connections as well, of course.

If you have a voltmeter with resistance measuring capability, you can do the following test on the transistor module:

This table was generated many years ago for analog meters, so a modern digital meter may give different resistance values -- the important thing is to verify that the presence or absence of any continuity.

As mentioned in an earlier post of mine to this thread -- use the TM1591 diagnostic procedures to narrow down the root cause of your symptom...

Chuck
 

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#17 ·
I have given this advise in other threads and it applies here as well.
Any time you have a no start situation you have to see what element is not present to make it start.
You must have spark,fuel,compression and all of it has to happen at the correct time.
Testing coils,TDC modules etc when you don't know what element is missing is chasing your tail around.
Any time I come upon a no start that is what I do.
If spark is missing then carry on checking coils etc.If fuel is missing then you are wasting time checking coils.


AJ
 
#18 ·
I too have the intermittent starting issue with my 322 and am about to lose my mind. Engine cranks but no spark at any of the cylinders using a spark tester. There is power to all three coils. the TDCM has power and ground at the appropriate connector pins per the technical manual trouble shooting procedures, and the transistor module continuity test checks out. I have cleaned every connector multiple times, have a fully charged battery, new fuses... started and ran great yesterday after cleaning the TDCM connectors, but again has no spark today, despite spraying everything with contact cleaner again. What an I missing????
 
#19 ·
Steve,

Looking at the wiring diagram I posted above you will see that the + side of the three coils is always powered with 12 volts whenever the hour meter is running (which is to say whenever the key is on and the safety circuits that are the inputs to the TDCM are satisfied...) What switches the coils and causes the spark at the appropriate times is the negative side of the coil that is driven by the outputs of the Transistor Module, which is in turn stimulated by the Pulsar coils at the correct rotation position of the flywheel. Here is some text from the TM1591 on how everything works...



Chuck
 

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#20 ·
Don't forget for the transistor module to do it's job it has to have battery voltage on the pink wire FROM the TDC module.
Don't overlook that.That is what I found wrong on my 92 when it had no ground at the coils.


AJ
 
#21 · (Edited)
Good point AJ.

The pink #820 wire from the TDCM passes through the X18 connector and becomes the pink/black #652 wire that goes to X26 (the connector that plugs into the Transistor Module) and from there continues to the X27 connector as the #654 pink/black wire. Across the X27 connector the orange wires then go to all the coil + terminals.

While measuring 12 volts at the coils does verify the proper working of the TDCM in regard to enabling spark, it does not by itself verify that the Transistor Module plugged in along the way and is making a good connection. Also note that there is a jumper in the X27 connector that branches the #654 pink/black wire to an additional pin in the connector that supplies power to the fuel shutoff solenoid (and the electric choke, if fitted...) via a red wire and the X28 connector.

Also, be sure to verify a good ground connection to the Transistor Module via the #140 black wire which is the other conductor in connector X18. A missing or intermittent ground here will cause the no spark symptoms for sure...

For a tractor the age of any model year of 322 which may have been kept outside for some of its life -- cleaning, verifying and inspecting these connections is very important.

Chuck
 
#22 ·
Thank you AJ and Chuck. You have both been invaluble sources of information. I think I've narrowed the problem down to the transistor module, though have been unable to detect any specific irregularities with the leads. I was tempted to bite the bullet and buy a used TM to swap out, but picked up a can of CRC electrical parts cleaner and blasted the connectors for the TM and TDCM once again. This had a much stronger spray than the cleaner I had used before and removed quite a bit of gunk that had been missed previously. She started right up three times in a row. Fingers crossed.
 
#23 ·
Chuck, thanks for the transistor module test chart. I had the schematic but did not see the test chart in the service manual. I have been struggling to get back into the shop to test the module but should be able to do it tonight. I'll get back with the results once I do a cold pre-test and then I'll try to do this again with the engine at operating temperature after it looses spark.
 
#24 ·
Ok, found an intermittent open leg on the transistor module. I had picked up a used one on ebay that checked out ok. Swapped the modules and the tractor runs great. Unfortunately it looks like the battery is not charging.....did I mention the deal I got buying this tractor that didn't run!?
 
#25 ·
Jtread,

Glad to hear that you were able to isolate your ignition issues to the Transistor Module and were able to substitute a good one to get running again. The regulator issues are usually related to bad connections or burned wiring (which can happen when the tractor tries to charge a failed battery...)
Do a search on this site for ideas on where to look to fix your charging issues, and start a new thread specific to that if you need to.

Chuck
 
#26 ·
Jtread

Agreed with Chuck,
Glad you got her going again.


AJ
 
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