YM SA424 SHUTS OFF

[TOwens-HT]

I have a 2018 Yanmar SA424 3 cyc with hydrostatic transmission that starts right up and runs for a while (30-40 mins) and then just shuts off like it ran out of fuel. It will restart immediately with no issue and run at idle, revs up no issue, but as soon as I try to go (forward or reverse) it shuts off immediately again. Will restart over and over, but shuts off when I try to move. I thought it was fuel related, but yesterday I put fresh fuel in and cleaned the fuel/water separator. It started right up and ran for about 40 minutes before it suddenly shut off again with the same results as above. After about an hour of letting it sit I tried to move the tractor and it started right up and ran with no issues so I parked it before it quit on me again. Before I dig into the fuel system I’m wondering if there’s a safety device that’s shutting it down or an electrical component that's getting hot and shutting it down? It just seems weird that it'll start right back up and runs for as long as I let it as long as I don't try to go forward or reverse. All fluids are full, engine temps is normal, just put fresh fuel in. Any assistance is much appreciated!

 

[winston-HT]

I would think your problem is with a safety switch. Might start looking at page 14-11 in the manual. <LINK_TEXT text="https://www.yanmar...1_424_OPERATORS-MANUAL_WEB_LR.pdf</LINK_TEXT>

 

[Realbeerad]

I have a 2018 Yanmar SA424 3 cyc with hydrostatic transmission that starts right up and runs for a while (30-40 mins) and then just shuts off like it ran out of fuel. It will restart immediately with no issue and run at idle, revs up no issue, but as soon as I try to go (forward or reverse) it shuts off immediately again. Will restart over and over, but shuts off when I try to move. I thought it was fuel related, but yesterday I put fresh fuel in and cleaned the fuel/water separator. It started right up and ran for about 40 minutes before it suddenly shut off again with the same results as above. After about an hour of letting it sit I tried to move the tractor and it started right up and ran with no issues so I parked it before it quit on me again. Before I dig into the fuel system I’m wondering if there’s a safety device that’s shutting it down or an electrical component that's getting hot and shutting it down? It just seems weird that it'll start right back up and runs for as long as I let it as long as I don't try to go forward or reverse. All fluids are full, engine temps is normal, just put fresh fuel in. Any assistance is much appreciated!

I would think your problem is with a safety switch. Might start looking at page 14-11 in the manual. <LINK_TEXT text="https://www.yanmar.com/eu/agri/wp-conte ... WEB_LR.pdf">https://www.yanmar.com/eu/agri/wp-content/uploads/sites/12/2023/02/EN_SA221_424_OPERATORS-MANUAL_WEB_LR.pdf</LINK_TEXT>

This is an older post which doesn’t appear to have gotten much traction. I am having the same exact problem. I have also found this problem in the Yanmar marine community. One of the posters in one of the marine communities I viewed while searching for similar problems finally had a tank cleaning company clean their fuel tank and found some debris. For future searchers experiencing similar symptoms, this is not a turbo issue although it can sort of look like that because mine is not a turbo model and is exhibiting the same symptoms. Therefore wastegate and any other turbo related systems are ruled out. This is an issue that affects Yanmar engines in marine settings as well as ag/ lawn care settings. I’m only looking for answers from people who have been through this and found what the basics of diesel maintenance and repair and diesel technicians are not aware of. This is not a “basics” issue, it is a Yanmar issue. I don’t post public questions until I’ve covered all the basics and I do have some training and experience in diesel maintenance and repair. It does act like fuel starvation, but only happens in gear or when the hydrostatic transmission is engaged. Starts and runs fine and works for about an hour then sputters and stalls to around and below idle speed, blowing blue smoke while it runs with a stutter, rpms can’t be increased, and no work can be done at all or engine will die. May or may not re-start trouble free, once it happens it continues to happen. If it doesn’t start right up again like nothing happened, it will not start again and stay running until after it cools down. Everything is clean and clear and/ or new. Started out of the blue with no increasing issues or warnings leading up to this. To me it seems temperature dependent and related to the hydrostatic transmission. ECM/PCM has crossed my mind. *Update, until yesterday I had never experienced this problem except when HST is being used and hydraulic systems working. I was trying to prep the site where my new shed is going, and could hardly make any progress at all before having to stop and let tractor cool down. Finally parked it where I can hose it off or work on it when it dies and set brake, relaxed all hydraulic systems, and cranked throttle to WOT in hopes off getting through whatever is causing this (if it’s water or sludge in the fuel. In this case WOT = about 3,500 RPM when to reach 540 RPM at the PTO = about 3,000 RPM, so no I don’t feel that is destructive behavior). It ran this way for between 20-25 minutes and then did it under no load. It is now easier for me to consider the fuel starvation path which could likely be trash in the tank or plumbing upstream of the inline filter. It did also cross my mind that the vent cap could be plugged or restricted eventually causing a vacuum on the tank, but cracking the cap open slightly does nothing to remedy.

 

[Realbeerad]

In retrospect I now believe I have been having this problem for far longer than I realized. I travel for work constantly and have little home time. In 2023 weeks began having reliability/ dependability issues with our hay guy, and far beyond when the hay SHOULD have been cut is when I actually had time to deal with it myself. Mowing hay with a compact tractor with a finishing deck is not ideal, and I found most of the fields required at least 3-4 cuts before it looked like work I could walk away from. Because the Hay had matured so much it was trying to go to seed, so there was a LOT of airborne chaff while I was cutting. Eventually I got a coolant temperature warning light. I opened the hood and the radiator screen was packed full of chaff. So I cleaned that off and pulled the air filter and knocked all the loose debris out of it. This cycle was repeated many times before I finished the fields, and it grew more frequent as I went. Because I had no previous issues like this with the tractor, I was paying attention to what I was doing and not the dash, so I don’t know how long the light had been on, and the problem caught my attention when the fuel starvation issue happened, which I had attributed to the temp switch, perhaps as a safety measure. From that point on I was watching for the coolant temperature warning light light. But I would start having this happen without the coolant temperature warning light and then though the engine was just ridiculously sensitive to any dirt in the air filter. Prior to all this I had had electrical issues with my new tractor. First the right rear turn signal/ running light/ brake light would burn out frequently. I just kept replacing the bulb. Then the fuel gauge quit working when the tractor was about a year old, so I called my Yanmar dealer and they came out and fixed it. I assumed they replaced the sending unit in the tank. Then my right rear light could not be restored by replacing the bulb, then I had no rear lighting at all. During all this time, the first 2 years of ownership, the tractor was used for mowing our property and some light clearing and some demo work and moving cut tree sections around the property to our burn pit. Also in this time, the throttle lever lost tension and I had to go into the dash to fix that. I don’t know if all this work could have affected the ECM/PCM and/ or wiring harness, but this is why I thought that could be the root cause of my problems. We have not had a garage or shed to keep my tractor in so it is outside all the time. I did open and inspect the rear wiring harness as far as I could looking for damage, but found none.

 

[bmaverick]

ONLY by fuel at a popular and active truck stop. Do not buy off-road diesel and it's old in the underground tanks.

On TBN, TractorForum and many active Ag sites, this is discussed to great extent. Microbes contaminate oils and diesel fuel. The slightest water or humidity in the fuel system can play the feed ground for the microbes.

A clean fuel system with fresh diesel is required.

PowerServe products will not restore the fuel system, you need to use a better product(s).

Seafom was originally engineered for diesel engines. Likewise Gumout Tune-Up.