Fuel Starvation Sea Ray 260 Sundancer 350 MAG MPI

[SARBlade]

Well, I had to pay for C-Tow to bring some fuel out to me the other night! Grrrr! I had over 1/2 a tank registering on the fuel gauge, however, the engine just died. I had fuel filters change in 2020, but only used the boat for about 50 hours in the past 2 years. So I thought, oh, I have a fuel gauge problem. Today I took out the fuel sending unit, moved the float to the top, the gauge read Full. Moved the float to the bottom, it read just under a 1/4 tank. So I re-calibrated the gauge and the sender through the Smartcraft gauge, and basically set the float at the appropriate 1/4 increment. Once complete, I checked the float with the gauge, and low and behold, it worked as it should. I then took my flashlight and dipped the tank. Its 1/2 full! So now I'm thinking i really had no fuel gauge issue at all. Now what have I got? I'm open to ideas. I'll order in filters (I think there are only 2 right, the main fuel filter (looks like an oil filter) and the fuel/water separator fuel filter (cartridge type)), and then change them.

Could it be an airlock? When I pulled the floor in the mid-berth to find the sender unit, the tank looked like it was deflated because of lack of air. Oh, and now here is some input to the community. The sending unit on a Sundancer 260 is not located in the mid-berth under the bed. I looked there because many posters on this site said that is where it is located. Well on mine, its located just behind the genset mounting platform, easy to get at.

Anyway, has anyone had a problem of the tank not letting air into it. The other night when I had a fuel delivered, I put it in, and maybe I released the airlock and the boat started, i don't know, but I am now hesitant to take the boat out because I'm not sure it the fuel pickup in the tank is not at the bottom of the tank or is there an air lock? Any help is appreciated. Thanks.

 

[Fill Ess]

I'm not as familiar with the 260 but I would think the tank near the mid-berth is the fresh water tank?

 

[Fill Ess]

For the fuel ... have you verified that both fuel filters are changed and the vent is clear?

 

[SARBlade]

For the fuel ... have you verified that both fuel filters are changed and the vent is clear?

I am ordering new fuel filters to replace, eventhough they were replaced only about 50 hours ago. As for the air vent, I'm not sure how I check that, its such a small line from the fuel filler cap down. I'm not sure if the little filter covering the airway has an obstruction or not, I can't see anything. Its a bad design because anything the air vent picks up could potentially just drop in the tank filler hole right underneath it. What is baffling is that I had the bought out for the better part of 3 hours, no problem, burnt a little less than 1/2 tank of fuel, no issues. Engine ran great. Then go out for 20 minutes at 3700 RPM cruise, then down to an idle troll speed, and it died 20 minutes later and wouldn't start. I then checked the cartridge fuel filter, easiest to take out, no water, and seemed fine. I did not have a fuel/water filter to change so I did not take that one off. I called for fuel, 5 gallons was put into the tank and I roared off. I thought had run out of fuel, now I know I didn't. I'll replace filters and look at that vent. Maybe a second vent could be put in directly through the hull?

 

[garybly]

Well, I had to pay for C-Tow to bring some fuel out to me the other night! Grrrr! I had over 1/2 a tank registering on the fuel gauge, however, the engine just died. I had fuel filters change in 2020, but only used the boat for about 50 hours in the past 2 years. So I thought, oh, I have a fuel gauge problem. Today I took out the fuel sending unit, moved the float to the top, the gauge read Full. Moved the float to the bottom, it read just under a 1/4 tank. So I re-calibrated the gauge and the sender through the Smartcraft gauge, and basically set the float at the appropriate 1/4 increment. Once complete, I checked the float with the gauge, and low and behold, it worked as it should. I then took my flashlight and dipped the tank. Its 1/2 full! So now I'm thinking i really had no fuel gauge issue at all. Now what have I got? I'm open to ideas. I'll order in filters (I think there are only 2 right, the main fuel filter (looks like an oil filter) and the fuel/water separator fuel filter (cartridge type)), and then change them.

Could it be an airlock? When I pulled the floor in the mid-berth to find the sender unit, the tank looked like it was deflated because of lack of air. Oh, and now here is some input to the community. The sending unit on a Sundancer 260 is not located in the mid-berth under the bed. I looked there because many posters on this site said that is where it is located. Well on mine, its located just behind the genset mounting platform, easy to get at.

Anyway, has anyone had a problem of the tank not letting air into it. The other night when I had a fuel delivered, I put it in, and maybe I released the airlock and the boat started, i don't know, but I am now hesitant to take the boat out because I'm not sure it the fuel pickup in the tank is not at the bottom of the tank or is there an air lock? Any help is appreciated. Thanks.

I had the same problem with my 320 sundancer, the low pressure fuel pump was bad, check fuel pressure, the gauge to check it with is cheap

 

[garybly]

I have cool fuel setup, not sure if you do

 

[Caveman22]

Spider webs can block the fuel tank vent and cause a shutdown after a while of running also. Use a mirror to check the vent if you're in the water. There is a little screen over the vent opening. But definitely check fuel pressure.

 

[SARBlade]

I have cool fuel setup, not sure if you do

I’m not sure if I have cool few or not, I suspect I do, I’ll wander down to marina today and have a look. As for check fuel pressure, I guess it’s over to YouTube as I have no idea how to do that unless the Smartcraft gauge has it? Thanks

 

[SARBlade]

Spider webs can block the fuel tank vent and cause a shutdown after a while of running also. Use a mirror to check the vent if you're in the water. There is a little screen over the vent opening. But definitely check fuel pressure.

Thanks, I did do a visual on the very small air vent inlet in fuel cap, nothing that I can see. I was looking at a Maxam 270 SC and that boat has a separate vent on the side of the hull, I think I like that better. Maybe my fuel cap is not allowing air into the vent?

 

[Caveman22]

That's possible that it doesn't have a side hall vent, if it would happen and you popped the gas cap and here's a sucking sound you know it's drawing a vacuum and not fuel. As far as the cool fuel system, you can find that on YouTube and It'll show you what it looks like.

 

[Gunn]

I’m not sure if I have cool few or not, I suspect I do, I’ll wander down to marina today and have a look. As for check fuel pressure, I guess it’s over to YouTube as I have no idea how to do that unless the Smartcraft gauge has it? Thanks

To check fuel pressure you'll need a fuel gauge. There is most likely a shraeder valve located behind the throttle body, on the fuel rail. The fuel pressure gauge just screws on there.

Even if you have the cool fuel setup, you can still have a low pressure boost fuel pump upstream from the cool fuel high pressure pump.

The fact that your engine started after awhile is interesting. I used to have a vapor lock issue. But that only occurred when I shut down for a few minutes after the engines were warm and it was hot outside. It wouldn't restart for a couple of hours. I solved that by adding those low pressure boost pumps. So that doesn't seem to be your issue. Could very well be the vent. I installed one of those noise/whistle things in my vent line so I know when my tank is almost full when refueling. When I hear that I know my vent line is unobstructed.

Tom

 

[SARBlade]

Oh, and I should say that I have had the engine at WOT of 4600 RPM when running it this summer to test everything and had no problems. That’s why I’m thinking it’s not a fuel pump problem. Will advise once the damn stores open here to get my filters lol!