YM1500 wont start air escaping near fuel pump?

[Torx]

Hello Everyone,
Ive had a very busy Spring and Summer working on everything but my little YM1500.. Poor tractor has been sitting alone in the dark recesses of my barn.
It's time to get this little monster to wake up again.

It would grudgingly start last fall after I replaced all the fuel lines, bled the fuel system and don't be shocked, spray a small amount of starter fluid into the intake. I bought some starting fluid that is lubricated and is designed for diesel engines. I use it sparingly.

Also, I could pull it for about 50 feet in say 7th gear with my YM226 and she would start right up.
Last fall, I pull started her and drove her around for 3 or 4 hours, burning through some fuel and replacing it with a couple of gallons of fresh fuel. It ran as smooth as silk and all the electronics, including the idiot lights, headlamps and blinkers were working great. I would wait a day or two and it would key start just fine. I backed it into it's spot in the barn last October, changed the oil, turned the fuel petcock off, drained the tank, replaced the fuel and air filter and closed the barn door.

Fast forward to this June. I finally had a chance to fill the tank with fresh fuel, turned petcock on, bled all the way to the injectors and as hard as I try, I cannot get it to start. The battery is fully charged, the starter is almost new, everything turns over just fine and even with a quick shot of starter fluid, I'm getting not even a cough!
If it were a gasoline engine I would be blaming the spark plugs or an electrical problem. I am getting plenty of fuel at the injectors and all bleed points.
I tried pulling it like last fall and am getting no start at all.

I was bleeding the fuel line at the screw on top of the banjo bolt that screws directly into the top of the fuel filter and a teaspoon or so of fuel ran down the left side of the fuel pump where the fuel pump mounts against the engine. There is a small 1/16'' gap that runs down the entire left side of the fuel pump. I know that there are shims underneath the fuel pump to get it to strike correctly and pump fuel to the injectors, but Ive never seen a gasket that is supposed to be on the fuel pump.

Anyway, after bleeding, some fuel was standing in that gap and as I turned the engine over, I saw air bubbles forming along the whole left side of the fuel pump. I thought, air in the fuel system, bad news..Put some sealant along the left side of pump, fix fuel problem.

I am now wondering what might cause air to escape from basically a hard point in the engine? Does anyone know what could be causing the air to escape or even get to this place? Will permanently sealing with a better sealant than the hi temp RTV I used to very little effect help? This tractor used to start on the first try before a "mechanic" friend burned up a starter and probably used a gallon of either on it after it got debris in the tank. Some kids or someone stole the gas cap and it got rained in quite a bit. The "mechanic" returned it with a burned up starter, a fried spark device for the thermostart system and a flat tire.

Could air here be telling me too do a ring job or maybe a whole rebuild. It ran so good last fall that I'd be surprised if it had anything major wrong but who knows?
i am not a diesel mechanic, only learning from trial and error and from all the generous help I received here from the nice folks Ive been fortunate to help me with my previous YM1500 (green) and my current YM226 that runs like a top.

Sorry for the overly long description but I wanted to give y'all some background and hope I have a small problem to fix. My last YM1500 almost drove me to the looney bin and ran me into the poorhouse.!!

Regards,
Torx

 

[winston1]

Not sure I am completely understanding but am I correct you are getting air bubbles where the shims are shown and pump bolted to engine? If so, the bubbles could be caused by crankcase pressure. Not talking about much pressure just a little blowing can cause bubbles. You are correct there is not suppose to be a gasket there. Check your crankcase vent assuring some varmit hasen't stopped it up. Yanmar Tractor Parts: FUEL_SYSTEM

When it was running what kind of blowby came out the tube? (#33) Yanmar Tractor Parts: BLOCK

 

[careyo63]

[Quote=everything turns over just fine and even with a quick shot of starter fluid, I'm getting not even a cough!

Check and make sure the Decompression Linkage is not stuck keeping the valves open. If they are shut and with nothing with the use of Either/Starting fluid it sounds like your going to have to Run a Compression Test.

 

[normde2001]

"a teaspoon or so of fuel ran down the left side of the fuel pump where the fuel pump mounts against the engine. There is a small 1/16'' gap that runs down the entire left side of the fuel pump. I know that there are shims underneath the fuel pump to get it to strike correctly and pump fuel to the injectors, but Ive never seen a gasket that is supposed to be on the fuel pump."
If fuel is leaking around the edges of the pump, no gasket or sealant is going to fix. That's an internal leak and will require a pump rebuild. I agree, sounds like a compression problem also. Maybe damaged pistons from too much starting fluid.

 

[Torx]

Hello Everyone, Thanks for the replies. I'm replying from my phone so please forgive me if I miss any questions or don't know everyone's names who replied
Winston.. Your correct. The pump is installed and used one shim to align properly. Its bolted in place and has been for 3 years. It has worked fine, before and after the gas cap problems.
It fits pretty tight into the pump well or pump housing on the side of the engine. There is a small gap around the whole pump that is consistent with my other YM1500. The air bubbles I saw were after I bled the fuel line leading into the top of the fuel pump. The fuel ran down the pump housing and some must've gotten into the gap on the left side of the fuel pump and some air escaping in small amounts from down beside the fuel pump and the engine housing to the left of the fuel pump in the small gap I mentioned started blowing bubbles with the excess fuel that ran into that gap from when I bled the screw on the banjo fitting that feeds the fuel pump from the fuel bowl. I was opening the screw while turning the engine over and that's why I mentioned a teaspoon of fuel trickled down beside the fuel pump. I don't have a fuel leak at all. I saw the bubbles there and thought the fuel pump might be sucking air in to the fuel system but the bubbles are coming out of the small and even gap on the left side of the fuel pump. I tightened the pump down after reseating it and making sure that I was getting good fuel output at the fuel lines that bolt onto the injectors at the top of the engine head.
The crankcase vent is fine and last fall it had very little blow by at all. Maybe a whitish smoke at higher RPMs but the blow by or lack thereof really surprised me. And it ran so darn good for three or four days with a key start, I was looking forward to a nice easy start this summer.

Carey
Thanks for the idea. I double checked the compression lever and it is hitting the valves just right and works fine. I've been using it to try to start this rascal and always use it for 10-15 seconds anytime I start any of my Yanmar tractors. I don't have an adapter to do a compression test and have never had any luck getting a injector out. I may have to break down and buy the Hoye puller or fashion something on my own. I will say that if you put your hand palm down and flat over the intake while you turn it over, your hand will get a circular hickey from the draw of air into the intake.

Normde2001,
Thanks for your kind input as well. I may have sounded misleading, but the teaspoon of fuel running down the fuel pump was from me bleeding the fuel line from the screw on the top of the banjo fitting that feeds the pump from the fuel bowl. I had one hand turning the key and one hand bleeding that fitting when I saw the air/fuel bubbles coming from the fuel pump area. There are no fuel leaks from the pump or anywhere else that I know of.

I appreciate everyone's replies and I hope that the way I replied to all of you at once, gets back to you properly.
If I removed the fuel pump and the shim, what is behind there. What could be causing a slight compression leak. Does the fuel injector pump butt up against a part of the piston track that isn't sleeved? Is it possible that a rod has knocked a hole in the piston housing? I'm talking about the portion of the piston track above the sleeve. I doubt that a hole could develop in such a heavy steel sleeve. Wouldn't a sleeve o-ring gone bad be allowing water into the oil? Could a piston ring gone bad be somehow forcing a small amount of air out of some junction behind the fuel pump. Obviously, I'm not familiar with what engine parts are near the fuel pump and is there a factory place for air and compression to be leaking and would this small leak be enough to create enough compression loss to not allow a cough when starter fluid is sprayed directly into the intake? I've put a blow dryer into the air intake briefly to warm the air some to try to help get her started. Could a valve or valves being out

 

[Torx]

Could a valve ir valves be out of adjustment causing the lack of fuel firing? Could there be any other place that compression is being lost or any other trick in someone's book that will keep me from tearing down a motor that ran like silk just 6 months ago. I can say that several " uhh hum mechanics" have put RTV on every surface where fuel might be leaking or drawing air into the fuel lines. The starter was burned up and I would venture to say that several cans of either have been used in an attempt to get it started. To me, the fact that pulling it to start it would build compression in the cylinders enough to start it where the new starter I bought wasn't turning the engine fast enough.
I just want one dependable YM1500 out of two that I've owned to start properly without dumping a small fortune into rebuilding another simple 2cyl engine.
I'm at wits end and have about $1300 in this tractor and want to break even when I find a buyer. Rebuilding the engine will cost me about $500 for parts and help.
thanks for all and any suggestions and I appreciate you listening to my rant.
Peace,
Torx

 

[winston1]

I would think the bubble blowing is the least of your worries. As I stated earlier the diesel on the flange and crankcase pressure is enough to cause bubbling. the injector pump just fits into the crankcase and is exposed to crankcase pressure. Nothing to worry about. I am going to lean toward Normde's' thought of maybe to much starting fluid. A compression test or tear down is about the only way to confirm compression loss.

Not saying this is your problem or this particular piston damage was done with ether but this is an example of what starter fluid can do in these little diesels. http://www.tractorbynet.com/forums/...525981-ym2000-piston-i-think-i-0620091413-jpg

 

[California]

First, look at the compression release linkage and verify it works as intended.

You can get a rough estimate of adequate compression, if cranking slows when you let go of the compression release. What do you observe doing this?

 

[clemsonfor]

Why would you drain the fuel for 6 months storage? Leave the fuel in it, just put fresh fuel with a fuel treatment for algae or similar in it and park it. Deisel is not like gas and can sit for years and still run just fine also the fuel will not hurt to be left in the system, you can turn the petcock off if you like if your worried about a leak or something but i would not remove the fuel unless you think it will be say 3 years or something till you were going to use it and then i probably would still leave the fuel in it.

Also i think you have low compression and or broken or stuck rings, possibly from eitther.

 

[clemsonfor]

That injector pump is bolted to the block inside there its open to the oil resivoir, so and fuel leaking internal will add to the oil level, meaning you would have deisel and oil mixing in the crank case. I think the rod its connected to has more to do with the timing and front of the engine than anything to do with a piston???

and a cracked ring would allow excess pressure to escape by the piston into the crankcase which would then bubble around the injector pump, but more quesionable is why is the pressure not escaping the path of least resistance which is the crankcase vent? A tube above the pump that should have a rubber hose comin out of it. its open to the oil and crankcase as well and pressure should escape thorugh that before forcing around the pump? Again like someone already sugessted is there like dirt daubers or something in that hose?