On the following day of a long journey in rough sea/weather with engine (2GMF) running non stop over 26 hours with no problems, the engine stopped on me while en-route. The phenomenon was that every few hours it would start smoking from the exhaust and dies. I managed to get it started by cleaning the water trap filter and getting rid of the air the air from the fuel system, but it kept dying on me. Any ideas on where to start looking for the trouble? It has been generally a reliable engine.
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Where to start?!
During heavy seas, when fuel supply in your tank falls below a certain level, it is sometimes possible for air to be introduced into the system causing the engine to stop.
During heavy seas, when fuel supply in your tank falls below a certain level, it is sometimes possible for air to be introduced into the system causing the engine to stop.
I would think fuel tanks ....
on a boat would be baffled to prevent just such a condition (sucking air).
on a boat would be baffled to prevent just such a condition (sucking air).
Tanks full?
Was your tank topped off before departure? There is two reasons keeping your tanks right to the top is a good idea. One, full tanks do not get condensation (which forms on the inside tank on the "empty" walls). Two, if you get rough going, the tank is full enough to prevent the full from sloshing away from from fuel line opening, which can introduce air into the lines. Fair winds. Doug
Was your tank topped off before departure? There is two reasons keeping your tanks right to the top is a good idea. One, full tanks do not get condensation (which forms on the inside tank on the "empty" walls). Two, if you get rough going, the tank is full enough to prevent the full from sloshing away from from fuel line opening, which can introduce air into the lines. Fair winds. Doug
Can occur despite baffling.
As I found out once in 11-foot seas when down to a quarter tank, it can, and does, happen despite baffling. The memory of bleeding air from the system down below during those conditions while inhaling the wondeful aroma of diesel (and the inevitable result thereof...) has served as a persistent reminder to keep my tank full at all times.
As I found out once in 11-foot seas when down to a quarter tank, it can, and does, happen despite baffling. The memory of bleeding air from the system down below during those conditions while inhaling the wondeful aroma of diesel (and the inevitable result thereof...) has served as a persistent reminder to keep my tank full at all times.
fuel pick up tube
I have an H34 with a 3GMF Yanmar and had the same problem. It would run fine for about twenty minutes and then die. It turns out that the fuel pick up tube in the fuel tank was clogged due to a screen ( which my mechanic tells me is unecessary) on the bottom of the tube was clogging the flow of fuel. I elimanated the screen and that solved the problem. Good luck.
I have an H34 with a 3GMF Yanmar and had the same problem. It would run fine for about twenty minutes and then die. It turns out that the fuel pick up tube in the fuel tank was clogged due to a screen ( which my mechanic tells me is unecessary) on the bottom of the tube was clogging the flow of fuel. I elimanated the screen and that solved the problem. Good luck.
Hypothesis testing
If your tank was full when you left, you might have burned 3/4 tank with a 2GMF. In rough weather, it is quite probable that you were sucking air. The problem is compounded when on one vs. the other motoring tack as the fuel intake tube is medial to the center axis of the boat. As suggested, keep you tank as full as possible. If this does not solve the problem, it could be a clogged fuel pick-up tube. I removed my fuel pickup tube and indeed there is a screen that fills with crud. I was surprised the engine could even run! My problem tended to occur at high RPMs and more frequently on one tack vs. the other. It seemed that crud on the bottom of the tank would get sucked around an already partially clogged screen intake. I solved the problem by cleaning the tank, removing the screen from the tube, and shortening the tube a bit. These are the situations which test one's logic and patience.
If your tank was full when you left, you might have burned 3/4 tank with a 2GMF. In rough weather, it is quite probable that you were sucking air. The problem is compounded when on one vs. the other motoring tack as the fuel intake tube is medial to the center axis of the boat. As suggested, keep you tank as full as possible. If this does not solve the problem, it could be a clogged fuel pick-up tube. I removed my fuel pickup tube and indeed there is a screen that fills with crud. I was surprised the engine could even run! My problem tended to occur at high RPMs and more frequently on one tack vs. the other. It seemed that crud on the bottom of the tank would get sucked around an already partially clogged screen intake. I solved the problem by cleaning the tank, removing the screen from the tube, and shortening the tube a bit. These are the situations which test one's logic and patience.
Let's not forget crud...
I focused on air as one obvious answer for a sudden engine cutout, but choppy seas can indeed create a suspension of algae and water (items which usually rest at the bottom of your tank until awakened) compounding the situation. When fuel begins to run low their proportion in the amount of fuel left will increase, and, at best tax your filter elements, and, at worst, possibly cause the clogs at the intake tube indicated by the other kind gentlemen.
I focused on air as one obvious answer for a sudden engine cutout, but choppy seas can indeed create a suspension of algae and water (items which usually rest at the bottom of your tank until awakened) compounding the situation. When fuel begins to run low their proportion in the amount of fuel left will increase, and, at best tax your filter elements, and, at worst, possibly cause the clogs at the intake tube indicated by the other kind gentlemen.
What color smoke?
You mentioned that the engine smokes and then dies. Is the smoke black or steamy? That will tell you something about the problem. If it is black, you are getting too much fuel. Can you pump the priming pump manually and get fuel? I do not know what steam indicates. Does the engine die abruptly or does it just gradually slow down and then die? My engine had a problem of a clogged exhaust riser where the cooling water is injected. It gradually got worse and worse and finally wouldn't start. Check it by removing it and you can clean it while you are at it. I check mine yearly just because of the problem I had before. Check the archives for more ideas.
You mentioned that the engine smokes and then dies. Is the smoke black or steamy? That will tell you something about the problem. If it is black, you are getting too much fuel. Can you pump the priming pump manually and get fuel? I do not know what steam indicates. Does the engine die abruptly or does it just gradually slow down and then die? My engine had a problem of a clogged exhaust riser where the cooling water is injected. It gradually got worse and worse and finally wouldn't start. Check it by removing it and you can clean it while you are at it. I check mine yearly just because of the problem I had before. Check the archives for more ideas.
More info ...
Some additional info on the problem: 1. Tank was 3/4 full when it happened 2. The engine would gradually lose RPM and dies (within 30 seconds appx.) 3. Smoke color was light Thanks for the ideas, it gives me plenty of things to inspect and try.
Some additional info on the problem: 1. Tank was 3/4 full when it happened 2. The engine would gradually lose RPM and dies (within 30 seconds appx.) 3. Smoke color was light Thanks for the ideas, it gives me plenty of things to inspect and try.
Exhaust color
According to the Yanmar Service Manual's trouble-shooting section light smoke is more often related to fuel issues as opposed to mechanical issues. Both loss of power and white smoke can be traced to fuel flow problems all the way from the tank to the injector and/or poor fuel quality problems. I should have asked first off if this happened only that one time during heavy seas, or if it has since happened in quieter waters, as this would have been a determining question as to whether the sea state was a factor.
According to the Yanmar Service Manual's trouble-shooting section light smoke is more often related to fuel issues as opposed to mechanical issues. Both loss of power and white smoke can be traced to fuel flow problems all the way from the tank to the injector and/or poor fuel quality problems. I should have asked first off if this happened only that one time during heavy seas, or if it has since happened in quieter waters, as this would have been a determining question as to whether the sea state was a factor.
You must also consider...
...your fuel tank vent and ensure that it's not clogged. Although not likely, reconsider the conditions. A clogged vent will cause a vacuum and restrict fuel passage to the fuel system. If you loosen/remove the fuel tank cap and hear air sucking into the tank when the seal is broken, then your vent is clogged.
...your fuel tank vent and ensure that it's not clogged. Although not likely, reconsider the conditions. A clogged vent will cause a vacuum and restrict fuel passage to the fuel system. If you loosen/remove the fuel tank cap and hear air sucking into the tank when the seal is broken, then your vent is clogged.
Sure sound like the pick-up tube
We had the same problem, the engine slowly died, then restarted after a few minutes, and the died it again. My understanding of the problem: The gunk in the tank get stirred up in bad weather and mostly clogs the pickup tube. You completly clog the tube, the engine runs lean (smoke?)and shuts down. When the engin dies, a small amount of the gunk drops off the pickup tube as the suction from the fuel pump is no longer present (but the majority of the screen is still plugged). After a few minutes you restart the engine and it runs until the suction again brings up enough gunk to replug the screen and the cycle start again. Take off the screen, and carry a spare filter, or better yet plumb in a second filter. Russell SV Allie Kat
We had the same problem, the engine slowly died, then restarted after a few minutes, and the died it again. My understanding of the problem: The gunk in the tank get stirred up in bad weather and mostly clogs the pickup tube. You completly clog the tube, the engine runs lean (smoke?)and shuts down. When the engin dies, a small amount of the gunk drops off the pickup tube as the suction from the fuel pump is no longer present (but the majority of the screen is still plugged). After a few minutes you restart the engine and it runs until the suction again brings up enough gunk to replug the screen and the cycle start again. Take off the screen, and carry a spare filter, or better yet plumb in a second filter. Russell SV Allie Kat
bad fuel
rafi..anychance you picked up some bad fuel..water etc...since engine ran well every time you emptied fuel separator and tank 3/4 full ...it has happened to me...
rafi..anychance you picked up some bad fuel..water etc...since engine ran well every time you emptied fuel separator and tank 3/4 full ...it has happened to me...
Another possibility...Fuel pump
I had a similiar problem with my 2GMF. In my case it turned out to be a loose screws on the fuel diaghram pump. After a long run along the Oregon coast, the engine started slowing then finally faultered to a stop. We were able to restart after about 45 minutes and it would run fine for 5 to 20 minutes and then repeat the process. The problem was persistent, even in a quiet marina. It took the mechanic two hours to find the problem. And it was the first time he had encountered this type of failure of the pump. So...keep those screws tight!
I had a similiar problem with my 2GMF. In my case it turned out to be a loose screws on the fuel diaghram pump. After a long run along the Oregon coast, the engine started slowing then finally faultered to a stop. We were able to restart after about 45 minutes and it would run fine for 5 to 20 minutes and then repeat the process. The problem was persistent, even in a quiet marina. It took the mechanic two hours to find the problem. And it was the first time he had encountered this type of failure of the pump. So...keep those screws tight!
Also interested
I just experienced an identical problem. Replaced a perfectly clean filter and problem has not (yet??) re-occurred. Pickup tube suggestion sounds good, but how do you get the @#$% thing out? Preferably without having the bottom portion drop into the tank!
Bill
I just experienced an identical problem. Replaced a perfectly clean filter and problem has not (yet??) re-occurred. Pickup tube suggestion sounds good, but how do you get the @#$% thing out? Preferably without having the bottom portion drop into the tank!
Bill- Status