Problems getting Yanmar tractor running.

[Sharkhunter]

Hi all,

I just signed up to this site this evening in hopes of getting some ideas on what I have to do to get my neighbors tractor running. It's a Japanese made "Forte" Yanmar 3 cylinder (series 3T) tractor. I'm guessing it's about 10 years old and has 560 hours on the clock.

A little history on what I'm dealing with....3 years ago the owner runs the tractor out of fuel. He attempts to get it re-fired, gets aggravated when he can't get it going, and leaves it parked in the barn for 3 years. He then takes it to a friend with some diesel experience who tinkers with it, and the guy ends up passing away from a heart-attack. I've now got the tractor and have no idea what was or wasn't messed with by the other guy.

What I've done so far in my attempt to get this running....

1)Replaced all of the the fuel lines on the engine. The old ones were dry rotted and cracking.

2)Replaced the fuel bowl gasket that was leaking.

3)Removed and cleaned the 3 valves from atop the injector pump. All 3 of the valves and components looked perfect, and showed no signs of being gummed up. The springs were not broken and looked like new.

4)Bled everything out. I really made sure there was no air in the system.

5)Fuel tank is full with fresh diesel.

When I crank the engine with the compression release pulled, I get a little bit of fuel from each of the 3 injector pump valves with the lines remove, but it seems inconsistent. A little mist is how I would describe it. I'm not sure that it's pumping enough. Another thing I noted is that when I try and start it, and then remove the steel injector fuel line from the injectors, it is under pressure, and a little fuel sprays out as soon as I break it loose. Is that normal? I tried to pull the injectors tonight but they were frozen up. I hit them with some pb blaster and will let that soak until tomorrow when I will try again.

It will run for a second or 2 with a shot of starting fluid, but will make no attempt to run without it.

Lastly, one other thing I'm not sure is normal is that when I crank the engine with the return line off the the last injector in the series just before the IP, it pumps fuel like what would be normally going into the injector pump.

If you guys have any advice, it would be much appreciated.

Tia,

Dave

 

[284 International]

1. Stop using starter fluid. Hopefully it not already damaged to the point of needing repairs from that. Ether WILL ruin your Yanmar.

2. The injector lines should emit a little bit of fuel each time the pump delivers fuel. It isn't much, but it should be consistent, both between pulses and injector to injector. If not, either your pump is bad or aren't getting good delivery to the pump. I would suggest checking the filter element in the bowl, and re-bleed. If fuel isn't pouring out of the bleeder screw atop the pump, you have an obstruction somewhere upstream.

3. If all that happened was running out of fuel, the new fuel and bleeding should resolve things. Since the guy "tinkered" with it, I'm afraid your troubles are rooted there. There's no sense in pulling injectors if you don't get consistent, adequate fuel to them. Start systematically and work easy to hard. You know there is trouble delivering consistent fuel pulses from the pump, so start there. Once you have confirmed the pump is properly delivering fuel, then start on the injectors.

4. Good luck, and let us know how you do!

 

[Sharkhunter]

1. Stop using starter fluid. Hopefully it not already damaged to the point of needing repairs from that. Ether WILL ruin your Yanmar.

2. The injector lines should emit a little bit of fuel each time the pump delivers fuel. It isn't much, but it should be consistent, both between pulses and injector to injector. If not, either your pump is bad or aren't getting good delivery to the pump. I would suggest checking the filter element in the bowl, and re-bleed. If fuel isn't pouring out of the bleeder screw atop the pump, you have an obstruction somewhere upstream.

3. If all that happened was running out of fuel, the new fuel and bleeding should resolve things. Since the guy "tinkered" with it, I'm afraid your troubles are rooted there. There's no sense in pulling injectors if you don't get consistent, adequate fuel to them. Start systematically and work easy to hard. You know there is trouble delivering consistent fuel pulses from the pump, so start there. Once you have confirmed the pump is properly delivering fuel, then start on the injectors.

4. Good luck, and let us know how you do!

Thanks 284. I'm pretty sure that fuel to the IP is not the problem. Filter is new, and the fuel pours out from the IP inlet fitting without any air bubbles. For what it's worth, it also pours out the return side of the pump just the same if I break that fitting loose.

 

[clemsonfor]

yea it should start easy, all you have to do once you run it out of fuel is to bleed the 3 screws after you put fuel in it. No taking lines off etc. 3 years is not long for a diesel to be sitting and it is fine if running then so don't worry about the injectors. and yes you will blow your rings apart or blow holes in the piston or damage the head in these yanmars, there are pics up of what starting fluid does to them.

 

[Sharkhunter]

yea it should start easy, all you have to do once you run it out of fuel is to bleed the 3 screws after you put fuel in it. No taking lines off etc. 3 years is not long for a diesel to be sitting and it is fine if running then so don't worry about the injectors. and yes you will blow your rings apart or blow holes in the piston or damage the head in these yanmars, there are pics up of what starting fluid does to them.

I guess that leaves me with replacing the injector pump? I'm just trying to make sure I don't spend any of my neighbors money needlessly. I won't use anymore starting fluid. :thumbsup:

 

[medic0648]

I guess that leaves me with replacing the injector pump? I'm just trying to make sure I don't spend any of my neighbors money needlessly. I won't use anymore starting fluid. :thumbsup:

You can probably take the injector pump to a machinist in the area. Ask a mechanic or 2 if they know of a place that rebuilds injector pumps. I've found a lot of small machine shops do hydraulic and injector pump rebuilds at good rates. There is a testing procedure for it if you have access to the service manual. If it's equivalent to a yanmar ym2200-3000 or 3600 aka jd850-1050 it's pretty easy to get ahold of service manuals.

 

[winston1]

Check the injector pump making sure the rack is moving as it shoudl. A long period of time and no use could lead to it sticking. What is the engine model or tractor model number? This pump is for a 3 cylinder but you can see the rack lever very clearly. The 3 cylinder will be very similiar. Yanmar Tractor Parts: INJECTOR PUMP - NEW!

 

[Car Doc]

Well nobody has mentioned this so I will it needs lots of compression to run on diesel fuel. A motor that's sat for 3 years can easily have dry rings and still have enough compression to run on either which is easily combustible and dangerous to engines.

I would try getting some engine oil in the cylinders and spin it with the compression release to work it in and not bend any rods and get that off the list of possibility's. I am presuming it has fresh fuel also fwtw. edit: just saw #5 my bad.

 

[careyo63]

It will run for a second or 2 with a shot of starting fluid, but will make no attempt to run without it.

Time to remove the Injector's and see if there spraying fuel. If they are run a compression check while there out and your know what you have. Air,Fuel,and Good Compression it should Run. If everthing checks out good then move to Stuck Injector Pump linkage. Did you check for the Exhaust to see if it's Clogged. Any Smoke out of it. I Don't recall it being mentioned.

 

[Sharkhunter]

Thanks to all for the helpful advice so far. I made a short video of what the injector pump is putting out with the tractor being turned over using the compression release. The fuel just kind of leaks over the top of the valves and doesn't seem to have any pressure behind it. I thought I'd see what you guys thought before I did anything else. Sorry for the crappy video. I was holding the phone with one hand.

Yanmar Tractor - YouTube

 

[Car Doc]

It spins plenty fast but I didn't see much fuel getting out maybe just my connection etc? Doesn't someone on here usually reccommend tapping on the plungers to free them up? I think thats worth a try also be carefull its just little pistons inside operated by the camshaft though.

 

[careyo63]

Those look to be for Bleeding the pump. Not Sure but on my YM2000 Pic.1 is the pump. Pic. 2 is the injectors. If your Injectors are similar First just loosen the Nuts and watch for fuel. If fuel shows up Remove An Injector and see what happens. If you have Spray a compression check is next while the Injector is out.

 

[Sharkhunter]

It spins plenty fast but I didn't see much fuel getting out maybe just my connection etc? Doesn't someone on here usually reccommend tapping on the plungers to free them up? I think thats worth a try also be carefull its just little pistons inside operated by the camshaft though.

I will definitely give that a try. I've run across posts where that was discussed. Thanks

 

[Sharkhunter]

View attachment 313722View attachment 313723Those look to be for Bleeding the pump. Not Sure but on my YM2000 Pic.1 is the pump. Pic. 2 is the injectors. If your Injectors are similar First just loosen the Nuts and watch for fuel. If fuel shows up Remove An Injector and see what happens. If you have Spray a compression check is next while the Injector is out.

Thanks for posting the pics. Your Yanmar resembles the one on my JD 750. This one I'm working on looks quite a bit different. I took some pictures that have better clarity than the video did. I will attempt to try and post them.

 

[sshaw]

I'm no expert on diesel engines, but it sounds like you might want to first make sure you are bleeding the system using the proper procedure for that engine.

Can you locate a user manual and follow the specific bleeding instructions for that model Yanmar?

I have a 3-cylinder Yanmar in my JD750. I replaced the fuel filter this past weekend so I was reading the bleeding procedure. The process described was a little complicated. The manual lists a series of steps, in about three different parts of the fuel delivery system, to be followed in a specific order. The instructions also mentioned some odd things, like NOT bleeding the line going to the middle injector.

Maybe none of the parts are bad and you just need to bleed it a certain way?

 

[winston1]

Still don't know the engine model, don't guess it matters but am I correct that is a priming pump below the injector pump and is it working?

 

[medic0648]

There will be a model an sn on the side og the engine. On my ym2500 I believe it is on the left side of the engine.

 

[winston1]

off the subject, but got to ask medic0648, were you an army medic?

 

[Sharkhunter]

I'm no expert on diesel engines, but it sounds like you might want to first make sure you are bleeding the system using the proper procedure for that engine.

Can you locate a user manual and follow the specific bleeding instructions for that model Yanmar?

I have a 3-cylinder Yanmar in my JD750. I replaced the fuel filter this past weekend so I was reading the bleeding procedure. The process described was a little complicated. The manual lists a series of steps, in about three different parts of the fuel delivery system, to be followed in a specific order. The instructions also mentioned some odd things, like NOT bleeding the line going to the middle injector.

Maybe none of the parts are bad and you just need to bleed it a certain way?

I don't have a manual for the tractor, but I'm 99% sure I have bled it out correctly based on all the Google searches I have done before posting a thread on this site. I'm fairly well versed in working with the larger diesels, especially the old Detroit's. I started at the fuel filter, and worked my way up the line all the way up to the injectors. No signs of air anywhere in the system.

 

[Sharkhunter]

Still don't know the engine model, don't guess it matters but am I correct that is a priming pump below the injector pump and is it working?

I had put in my original post that it was a 3T series engine. I scraped some paint off the tag on top of the valve cover and was able to decipher....3TN75. You're correct there is a priming pump below the IP. It seems to function fine. When I break the inlet banjo fitting, fuel pours out, and when I press the primer lever on the primary pump with the fitting still open, the fuel really comes out. I pulled the cover on the primer pump thinking there might be a screen filter inside, but no such luck. I don't think I have any restriction issues going into the IP.