Engine seems to run out of fuel

GCHOG

GCHOG

Active Member
Mar 25, 2016
149
Bass River, Viking Marina, South Jersey
Boat Info
2006 Sea Ray 260 Sundancer
Engines
6.2 Bravo III
Hi all , hope all are well. Having a problem with the boat; here's the basics.
-06 260 DA
-6.2 single engine,, 615 hours
- B III drive
Started the season fine after winter layup. Problem began about 2 weeks ago . Engine starts, runs fine at start-up, leave the marina , jumps up on plane, go about a mile and boat starts to stumble and die like its got a fuel problem. Drop back on throttle (to about 3500 rpm) and it runs so /so. Progressively gets worse till boat is barely running.
I replaced both fuel pumps (high and low pressure), (with OEM Merc pumps) and fuel filter (with disc) filter 3 times and it still has the problem . No indication of clogged filter(s) at all and no junk in Cool Fuel housing. No indication of bad fuel either.
I've checked all around the engine to see if any wiring may be bad and see nothing wrong. All temps, oil pressure , voltages, water pressure are good, everything seems ok.
Anyone ever have a similar issue ?, if so , what was the problem ? ,, I'm at my wits end ,, thanks in advance ,,,
 
It almost sounds like vapor lock. Have you checked actual fuel pressure on it? Perhaps the pressure regulator on the fuel rail or the IAC have failed. Have you checked the engine for any codes?
 
When the issue occurs has the pressure been verified/stable on the rail? Start there first….if it checks stable then begin investing plugs, plug wires, crankshaft sensor, camshaft sensor, IAC, injectors and coil packs.
 
3rd in line on the tank vent. If not venting properly, will get progressively worse until it won't allow fuel out of tank and starves the engine

Start at the cheapest / easiest and work toward the hardest / most expensive fix
 
The fuel tank vent makes alot of sense, thanks. I really can't get a good look at the tank, but I'll start there . I don't have a code reader but will ask around and see if someone has one. thanks to all.
Any more ideas would certainly be welcome, the more the better. Thx,,,,,
 
GCHOG said:
The fuel tank vent makes alot of sense, thanks. I really can't get a good look at the tank, but I'll start there . I don't have a code reader but will ask around and see if someone has one. thanks to all.
Any more ideas would certainly be welcome, the more the better. Thx,,,,,
Click to expand...

Check the tank vent fitting on the side of the hull. The screens tend to plug up over time. Spiders and wasps, for some reason, are attracted to the vents and plug up the screens with all kinds of crap.

Once the screen can't flow air, tank can't vent.

Also check your "Anti-Siphon valve" on the tank. They do go bad, too.

Been there, done that.
 
Thank you,, I know this is gonna sound stupid, but, where does the vent hose go to ? I don't think I have a vent fitting on the hull,, could it run along side the fill hose somewhere ? I'm going down today to continue to work on it, but would like to know what I'm looking for ,
Also, where would an "anti-siphon" valve be located ? ,, in the fill hose or right at the tank ? ,,,
 
Some boats have the vent built into the fill assembly. There is a screen in there too sometimes. If you have a 1-1/2" and a 5/8" hose going to the fuel fill, then yours has that setup.

The anti siphon valve is in the the tank fitting where the fuel to engine line connects to. It is a spring loaded valve that has been know to fail, causing what you are seeing. Easy / cheap fix if that is indeed the problem. One way to check is pull it out of tank and replace with a regular barb fitting and see if problem goes away. If it does, install a new anti-siphon fitting.
 
Post says you replaced the filter/separator, did you put the gaskets back in correctly? If not it will allow air to get into the system.
 
Bill Curtis said:
Some boats have the vent built into the fill assembly. There is a screen in there too sometimes. If you have a 1-1/2" and a 5/8" hose going to the fuel fill, then yours has that setup.

The anti siphon valve is in the the tank fitting where the fuel to engine line connects to. It is a spring loaded valve that has been know to fail, causing what you are seeing. Easy / cheap fix if that is indeed the problem. One way to check is pull it out of tank and replace with a regular barb fitting and see if problem goes away. If it does, install a new anti-siphon fitting.
Click to expand...
I will definitely check that , thx
 
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