Have you had or heard of this problem? After running for a while, my 1980-ish 3GMD just cuts out- very smoothly- and won't restart. This doesn't happen every time I take the boat out. It sounds as if someone just shut the fuel flow off. A thorough check (and recheck, check, check) of the fuel lines, filter, fuel pump, Raycor, air cleaner, etc., turns up nothing. When I check for air, there is fuel flow. After resting for a few hours or so, it will restart. Somebody suggested that the pickup in the tank is grabbing a clump or fleck of something and holding onto it until the engine vacuum relaxes. I put a new fuel tank in the boat a few years ago and I have filtered every drop of fuel through a filtration funnel when fueling. Thanks in advance for sharing any thoughts on this.
Yanmar 3GMD Just Shuts Off, Restarts Later
- Thread starter Hongo
- Start date
Just a thought.
If there is no fuel issue as you say, then I would suspect electrical. As the engine heats up the electrical connection opens up and the engine stops. (just like turning the key switch off, not recommended) When the engine cools down the connection is remade and you can start the engine. I would check the connections that are in series with the key switch.
Good luck
If there is no fuel issue as you say, then I would suspect electrical. As the engine heats up the electrical connection opens up and the engine stops. (just like turning the key switch off, not recommended) When the engine cools down the connection is remade and you can start the engine. I would check the connections that are in series with the key switch.
Good luck
It can't be electrical, once the diesel is started no electricity is required to keep it running. All it needs are fuel and air. Were you underwater when this happened? It is starving for fuel somehow.
OK maybe it is electrical do you have an electrically operated fuel cutoff somewhere?
I like the fuel vent suggestion. as fuel is burned a vacuum forms in the tank starving the motor. After sitting for a while the vacuum is gone and the engine can run
Next time you go out, take your fuel cap off right after it conks out. Maybe you hear a whoosh of air and maybe it starts right away.
OK maybe it is electrical do you have an electrically operated fuel cutoff somewhere?
I like the fuel vent suggestion. as fuel is burned a vacuum forms in the tank starving the motor. After sitting for a while the vacuum is gone and the engine can run
Next time you go out, take your fuel cap off right after it conks out. Maybe you hear a whoosh of air and maybe it starts right away.
Racor filter head could be fouled. That's what happened to my engine. I polished fuel, changed brand new filters 3 times for just in case, changed Fuel Lift Pump, changed fuel hoses, send for service both Injectors...all to no luck. Was planning to dismantle high pressure pump but decide to disconnected fittings for Racor filter head, surprised to find little fuel flow out. Found lots of gunks foul the head.
Yours may differ but worth a check before you start doing other bigger stuff like I did.
See photo. One side is fouled up.
Ken Y
Yours may differ but worth a check before you start doing other bigger stuff like I did.
See photo. One side is fouled up.
Ken Y
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Ken's right.
Fuel Starvation and The Obscure Ball Check Valve
On September 20, 2019, I was motoring back from a few enjoyable nights at my favorite local anchorage when I experienced a fuel starvation issue for the first time in my boat. We have sailed Aquavite since 1998. The engine simply sputtered and died, would restart after a few minutes and die...
forums.sailboatowners.com
How fine is the filter? Some folks like to overdo it (too fine) and end up very quickly with a plugged filter. I think 20u is the right number but you can buy 2u filters that will plug very quickly. Fuel starvation.
Some Racors have a check valve in the housing, and most people don't know they're there. If there's a nut or screw in the top of the housing, remove it and look inside. Could be plugged there.
Is the engine fitted with an electric fuel pump? When they start failing they will heat up and quit pumping and as soon as they cool they are good again until they finally die.
My John Deere lawn tractor was shutting off about 20 minutes into my run. I first thought fuel filter was clogged. I disconnected the hose, and heard What I thought fuel Running into the tank. I could blow through the fuel filter. I put it all back together and she started right up, and finished the mowing.
Next time out, same thing. Removed the fuel filter heard the same “gurgling“ sound of fuel in the tank. Engine started right up.
Dawned on me later that the tank vent was plugged (it is in the fuel cap)...and when the vacuum got high enough, the fuel pump could not overcome the vacuum and the engine would die. Open the fuel cap (or pull the fuel filter off like I did) and break the vacuum. Then the engine would run.
So, the lesson is, where is your tank vent and is it open?
Greg
Next time out, same thing. Removed the fuel filter heard the same “gurgling“ sound of fuel in the tank. Engine started right up.
Dawned on me later that the tank vent was plugged (it is in the fuel cap)...and when the vacuum got high enough, the fuel pump could not overcome the vacuum and the engine would die. Open the fuel cap (or pull the fuel filter off like I did) and break the vacuum. Then the engine would run.
So, the lesson is, where is your tank vent and is it open?
Greg
yanmar recommemnds either a brand new copper washer (which they'll sell to you at a huge price,) or annealing the old one to reuse it. a possible leak due to old washer being un annealed and re used is worth checking.