yanmar 3gmf troubles

[bob45]

Hi all,

I'm having a little trouble with my yanmar 3gmf and am hoping someone here may be able to help. here's the scenario:

I was out in some decent waves the other night and lost power while at idle, flaking the sail on my way back in. The engine started back up, then stalled in a couple minutes. It would crank after that but not turn over. I got towed in. I thought that maybe it stirred up some gunk or possibly got some air in the line, if maybe the fuel sloshed away from the pick up tube.

I changed both filters, then primed the engine opening first the bleed screw on the secondary filter, then the bleed screw on the injector. The engine fired up. i ran it at idle and half throttle at the dock for maybe a half hour. No problems, actually sounded better than it did before lol.

Later I headed out for a sail, after getting on the lake under power, about 20 min, the engine didn't die, but started to lose power and then be ok, then lose power and so on. I killed the engine and had a sail. Fired it up to come back in and it died after acting sporadic for about 5 min. I went below and bled it again at the injector, got it started and limped in, nursing the throttle whenever it felt like it was gonna die.

Back at the dock, I bled at the injector again. I went past the point i thought was good, just to make sure. I fired up the engine just fine and it ran well at idle, then I gave it half throttle and got some thin white smoke. None at idle, only with throttle. At this point I thought it might be time for some insight?

So I'm not sure where to head from here. Any insight would be much appreciated. TIA!

 

[dLj]

I had a similar problem. Turned out there was one banjo fitting in the fuel line that was just not quite snug enough. No idea if that could be your problem but that gave me almost identical symptoms.

dj

 

[bob45]

shoot, now that you say it... I have noticed that sometimes it leaks a little from the banjo fitting right before the filter. I'll try tightening it

I had a similar problem. Turned out there was one banjo fitting in the fuel line that was just not quite snug enough. No idea if that could be your problem but that gave me almost identical symptoms.

dj

 

[kloudie1]

Any air leak in the fuel system between the top of the tank and the discharge of the lift pump can do that. That includes filter gaskets, banjo fittings and the fuel line itself. Additionally, many fuel pickup tubes have a small gauze screen at the tip Inside the tank. It can get fouled and cause your symptoms also. If you have that screen, most folks remove it and let the primary filter do it's work.

 

[Don S/V ILLusion]

Any air leak in the fuel system between the top of the tank and the discharge of the lift pump can do that. That includes filter gaskets, banjo fittings and the fuel line itself. Additionally, many fuel pickup tubes have a small gauze screen at the tip Inside the tank. It can get fouled and cause your symptoms also. If you have that screen, most folks remove it and let the primary filter do it's work.