Re: Engine codes on 1995 (ford) volvo penta
Hmmm, no codes, not enough speed. Change fuel filters, check fuel vent for obstruction, check bottom of hull for dirty, hows the propeller?
To answer you question.
The anti siphon valve is a ball valve that only allows fuel to flow when there is suction. It won't flow fuel with just gravity. I don't have a small enough vacuum tester to check for what value it should run, but here's what I did to check mine.
First disconnect battery, 2nd work in a well ventilated area with no open flame, fuel vapor can ignite from many sources of flame and spark.
Remove fuel line from the anti siphon valve. This will be a pain if it's like mine, the rubber line fits tightly over the barbed end of the valve, if there's enough rubber line, slit about 3/4 to 1" of line and cut back that much. If you have to keep all the length you'll need a 90 degree pick to stick between the valve barb and the hose, work the pick around the inside of the hose to work the hose off the barb.
Then unthread the valve from the tank fitting. More advice here, if it's stuck on there, and it probably is - get a wrench on the tank outlet fitting and a wrench on the valve, use the wrenches against each other to turn the valve so you are not putting force on the tank fixture.
Once you have the valve out inspect it well, clean it with carb cleaner or fuel, move the ball with a plastic probe, clean it some more. If it doesn't work perfectly just replace it, the part is usually less money than the effort to remove it.
When reinstalling you put on a bit of teflon pipe sealer, not tape, and snug it down.
BTW I have a carburetor boat and a low pressure fuel pump at the engine. On fuel injection do you have pump in tank with pressurized fuel line(s)? Is there a return loop fuel line? Reason I ask is there would be no anti siphon valve if the fuel was plumbed like a Ford car or truck EFI. Or does it pull fuel up to the pump and then send it on to the engine? That method uses the anti siphon valve.
