[dishawjp]

All,

I have a 2003 GX 345 that only has about 115 hrs. on it that I have almost never mowed with, but generally used with the front blade for maintaining the trails I have in the woods, snow removal, and other similar types of work. It's always performed well for this type of work. It has the 20 hp liquid cooled engine.

This past weekend, I decided to put the mower deck on it and mow a field on the property. The field is probably a little over an acre and had only been mower once before this season, and the grass was pretty thick. It was also pretty warm out. After about an hour or so of mowing, the engine quit. I could get it to restart, but it would only run for a few seconds and then die again.

I walked back to the barn to get my 212 to tow it back, but decided to get some lunch first, and when I got back out there, maybe an hour or so, the GX 345 tractor started and ran fine, and I was able to finish mowing the field and drive it back to the house.

When I got it back to the house, I shut it down and got a hose to clean the mower deck off, but again, it wouldn't stay running until I let it cool off for an hour or so.

It's a water cooled engine, I did clean the radiator screen off when it first died in the field, because it was slightly plugged. Coolant level was normal and I did a complete coolant flush on it two years ago. It didn't boil over, and I'm stumped.

Could an electrical ignition component be overheating? Could the fact that for years, it's never been run hard at full throttle for any length of time be the problem? Is vapor locking an issue on these engines? The engine temperature light never came on that I noticed, and like I said, it didn't boil over.

Any thoughts or suggestions greatly appreciated.

Thanks in advance,

Jim

 

[Jimbochap]

http://www.mytractorforum.com/showthread.php?t=126538&highlight=ignition+coil+gx345

 

[dishawjp]

Jimbochap,

Thanks for the reply. I guess I'll start by checking out the ignition system and the fuel filter. My problem was different from his, in that mine will always start, but dies quickly if it's hot. His wouldn't start easily, but ran well once it did start. I probably have an ignition component overheating.

Thanks again for giving me somewhere to start.

Jim

 

[Jimbochap]

Jimbochap,

Thanks for the reply. I guess I'll start by checking out the ignition system and the fuel filter. My problem was different from his, in that mine will always start, but dies quickly if it's hot. His wouldn't start easily, but ran well once it did start. I probably have an ignition component overheating.

Thanks again for giving me somewhere to start.

Jim

I would think Coil, you have 2

 

[dishawjp]

Jimbochap,

I thought that I would wait for it to misbehave and then check each of the plugs for spark. If one fails to spark, then I would go for the coil for that plug since the plugs were new two years ago and only have about 20 or so hours on them, they should be good. If both fail to fire than I would go further up the line, like the ignition module. Also, there's a solid state card... I don't really know what that does, but maybe I could bring that into the dealer and have it checked out.

I'm also not entirely ruling out vapor lock or a fuel issue yet, although I've never seen a fuel pump quit and then work again, and there is no fuel leakage. The fuel filter is also worth a look at even though it isn't very old either.

Thanks again!

Jim

 

[Harryc]

Check for the vent hole being plugged on the gas cap.

 

[dishawjp]

HarryC,

I just thought of that last night and that will be the first (since it's the easiest) thing I check when I get back to my camp on Friday afternoon. I did some more reading on the forum last night and saw that that was a common problem with these machines and it does kind of seem like a fuel problem.

I will post after I have tried a few things and get it fixed to let all here know what the problem finally does turn out to be.

Thanks!

Jim

 

[dishawjp]

All,

Well, I checked the fuel cap to see if it was the culprit, but was able to blow through it easily. I mowed the lawn Friday and it seemed to be fine for about an hour or so, but just as I was finishing up, it started to die a couple of times. I had to shut down the mower and let the engine get back up to full rpms before I could reengage the mower and continue mowing.

I had to move it out of the barn on Saturday and Sunday to get my 212 out to use, and the 345 started, but needed to be cranked a lot more than normal before starting.

Now I'm wondering if it might be the fuel shutoff solenoid. Maybe it's getting weak and not opening right away and maybe shutting down after being held open for too long. Not sure if that's reasonable, or if that's how these things fail... maybe I'm just hoping for an easy and inexpensive fix, In any event, does really act more like a fuel problem than an electrical one.

Anyway, I have a long weekend coming up and I should be able to spend some more time on it.

Thanks for all your input.

Jim

 

[man4mopar]

I thought HarrC nailed it with the fuel tank vent but sounds like not it, perfect symptoms too darn.

How long has it been since the fuel filter has been changed? 2003 model and been 10 years with only 115 hours I am guessing it has sat with fuel for some time. May have some varnish built up some place. How fresh is the fuel?

Getting to a point that I would be testing fuel pump pressure and flow. Removing the carb to clean/inspect the internals and do a leak down test on the engine at both cold and operating temp.

 

[gt275]

My guess would be the Ignition Delay Module or Time Delay Module. Same thing happened to mine at about 150 hours. They are known to be intermittent at times and they are fairly inexpensive ~ $23.
I highly doubt it's a fuel filter problem because it wouldn't run for a long period of time and then quit and then be able to start it again a short time later.

 

[dishawjp]

Man4Mopar,

It had been sitting for several years when I bought it two years ago. At that time I drained the fuel tank, cleaned the carb (had to it was heavily varnished and wouldn't run), replaced all the fluids (oil, hydraulic fluid. coolant), replaced the plugs, fuel filter, main drive belt, and etc. I use only premium non-ethanol fuel in all my little engines and it is fresh.

What do you mean by a "leak down test"? What should the fuel pressure be? I did check the fuel pump flow when I did the rest of the work on it two years ago and it would be simple to check that again and the fuel pressure.

Thanks,

Jim

 

[man4mopar]

Man4Mopar,

It had been sitting for several years when I bought it two years ago. At that time I drained the fuel tank, cleaned the carb (had to it was heavily varnished and wouldn't run), replaced all the fluids (oil, hydraulic fluid. coolant), replaced the plugs, fuel filter, main drive belt, and etc. I use only premium non-ethanol fuel in all my little engines and it is fresh.

What do you mean by a "leak down test"? What should the fuel pressure be? I did check the fuel pump flow when I did the rest of the work on it two years ago and it would be simple to check that again and the fuel pressure.

Thanks,

Jim

I haven't looked into that fuel pump spec wise but I would guess it is around 1 to 5 psi so not to over power the float. Flow is the important part though to keep that fuel bowl full.

I have read what GT275 mentioned on the ignition delay module being a known issue. But the symptom of it dying down and then coming back to rpm slowly with the mower disengaged I lean towards fuel starvation. I would think the electrical issue would result in a shut down. Hard to say though, have you checked for spark when it dies and will not restart?

 

[man4mopar]

Man4Mopar,



What do you mean by a "leak down test"? Thanks,

Jim

Forgot to answer this. Leak down test is when you remove the spark plug then install a hose similar for a compression test but instead of a gauge and turning it over like a compression test.(Vary important to have the crank held in position either by a long breaker bar or something as it will want to turn over, depending on pressure etc. it can spin with great force making a hazard) You use a air compressor and a regulator then charge the combustion chamber with air pressure, piston at TDC of compression stroke. Then listen for air leaking, if hear air in intake the intake valve is faulty, hear air in exhaust the exhaust valve is faulty. Will always hear a little in the crank case as the piston rings are not a complete seal.
A lot of time a percentage is good to know. If regulator is set to 100psi the psi it shows when connected to engine and leakage will be in percent. Example hooked up and regulator reads 80psi you have 20 percent leakage. Small engines leak less then larger engines. General rule is 20% leakage is ok on small engines, generally when new or fresh rebuild they are in the 5-10% range. Shouldn't hear anything out the intake or exhaust though.
I don't think you have a issue in the engine but is a quick test to perform and I do them often to rule out that part. As leaking valves have caused some interesting engine performance issues.

 

[dishawjp]

GT275,

Thanks for the tip on the ignition delay module. If a symptom of its failing is intermittent dying and then restarting after a cool down, then that might be the problem and for $23 its worth a try IF the problem turns out to be ignition and not fuel. Earlier, Jimbchap suggested that it could be a coil problem and they can't be too expensive either, so if I eliminate fuel issues I may just spring for the module and a pair of coils. First, I want to check out the fuel flow (it's easy and doesn't cost anything) and if it seriously quits for long enough, I can check for spark which would indicate coil or module. The problem with checking for spark now is that once it quits, by time I walk back to the barn, get some tools and pull a plug it would probably be ready to run again. I'm halfway tempted to continue running until it REALLY quits so that I can troubleshoot it better.

Until I get back to me camp this weekend and can play with it some more I'm a bit stuck, but am tempted to at least see if I can just replace the fuel shutoff solenoid (hope that's not too expensive and not an entire carb) and the ignition delay module. If neither of those solve it, then I'll run the leak down test, but this thing really runs strong when it's running and I find it hard to believe that I have a burned or broken valve.

Thanks to all for your advice and helping me through this. I promise that once I do get it fixed I'll post about it.

Jim

 

[Harryc]

Uh...you'll probably want to make good and sure it's a fuel shutoff solenoid before you spring for one. Deere part# M138477
http://www.greenfarmparts.com/John-Deere-Solenoid-M138477-p/m138477.htm

 

[dishawjp]

HarryC,

Wow and thanks! I was thinking that a little solenoid like that would be about $20.

Jim

 

[dishawjp]

The saga continues.

I replaced the ignition delay module this morning and mowed until the tractor died again. It ran for about an hour. This time I did some diagnostics. It wouldn't restart, but I had good spark on both plugs, but if I poured gas down the carb, it would start and run. I thought it might be the fuel shutoff solenoid because I couldn't hear it click when I turned the key on and off. To be certain it was the shutoff valve and not something else not putting power to it, I pulled the the wire off the solenoid and ran 12 volts to it directly from the battery. Bad idea... I cooked the solenoid; it must use a reduced voltage. Stuff like that happens when you're stuck in a field a few hundred yards from the house or barn and don't have a multimeter Anyway, I pulled the solenoid and disabled it so that it couldn't shut off fuel flow. I won't say how in case it's considered a safety related issue. I did pull the fuel line to check the pump, and it was pushing fuel, but I wasn't impressed with the flow. After sitting for an hour or so, It did start and run again for about 15 minutes of so before dying again.

Sooooo...... I'll be off to the John Deere dealer for a fuel pump and a new filter to see if that does the trick. I've never seen a fuel pump work for a while, then get weak when it's been run for a while, then work again after sitting for a while, but now I don't know what else to try.

One question though, what is the purpose of the fuel shutoff solenoid? Safety or to prevent fuel from pushing past the float valve in the carb?

In the mean time, any suggestions or insights greatly appreciated and thanks for all the information and help given so far..

Thanks!

Jim

 

[man4mopar]

The saga continues.


One question though, what is the purpose of the fuel shutoff solenoid? Safety or to prevent fuel from pushing past the float valve in the carb?

In the mean time, any suggestions or insights greatly appreciated and thanks for all the information and help given so far..

Thanks!

Jim

Seems they use it to prevent back fire and or fuel pooling. Turn the key off the delayed ignition keeps firing for a given time. Fuel shut off valve stops more fuel from filling the bowl and your engine stops and no extra fuel is pulled. It will also act as a fuel stop if the float stop isn't sealing 100%, so safety and no back fires yes.
Definitely have a fuel problem from the sounds of it. Hope the fuel pump and filter sort it out.

 

[dishawjp]

All,

Well I replaced the fuel filter and the fuel pump last night. I ran the tractor for over an hour and it seems to be running fine now. I didn't have a lot of tall grass since I had mowed almost everything over the weekend, but it does seem to be cured now.

I did notice that without the fuel shutoff solenoid, I sometimes get a backfire, but if I let it run for about a minute or so under no load at half throttle and then at idle for another minute or so, I don't get the backfire. I'll have to think about replacing the solenoid for $140.

Thanks to all for your help and suggestions!

Jim