Gas?- PLEASE HELP!!!!

[kyhemi57]

Hi,
Quick question.

Have a 3.0l-4cyl Mercruiser. Engine will turn over but is not getting any gas. Took the fuel pump off, and the spring still moves freely and you can hear the pump moving inside. The hose going to the tank does not have any gas coming out of it and I just added around 15 gallons of gas to empty tank. I blew air into line hoping to clear any obstructions, and still no gas would come out of line. Im assuming it should be gravity fed and gas should freely flow out of the tank through this line to the fuel pump, right?

Ideas?


Thanks.

 

[chumstain]

Re: Gas?- PLEASE HELP!!!!

not exactly..the fuel line goes to the top of the tank then through a fitting with a check ball in it..you shouldnt be able to blow back to the tank. only suck..try to suck fuel from the fuel line till you get gas then connect it back to the pump pour some gas into the carb,not much just about a antifreeze cap full or so and try to start it again
i have had to do this to mine when i ran it out of fuel

 

[Scott Danforth]

Re: Gas?- PLEASE HELP!!!!

how long did it sit without fuel?

 

[chumstain]

Re: Gas?- PLEASE HELP!!!!

about a week

 

[jimbo_jwc]

Re: Gas?- PLEASE HELP!!!!

Should'nt went dry in float bowl.Mine was dry in a month .Air should open anti check into tank ,It's checked for free flow out of tank in case of hose break leak .Line from tank has to be air tight and flooded for fuel pump to work right.Fill mercruiser carb through top to float bowl and it will run till every thing fills and purges if not than leak some where and can suck air and not leak fuel .Pump pulses fuel line when full to open siphon valve air intrusion not solid to open to tank .

 

[kyhemi57]

Re: Gas?- PLEASE HELP!!!!

Hooked a primer bulb to gas line coming direct from gas tank and hand pumped for 10 mins and could get no gas....now what??

 

[Bondo]

Re: Gas?- PLEASE HELP!!!!

Hooked a primer bulb to gas line coming direct from gas tank and hand pumped for 10 mins and could get no gas....now what??

Ayuh,.... Obviously, there's a Problem with the Tank, it's fittings, or the lines...

Ya gotta Look, to see exactly Where...
I'd start with the tank's outlet fitting,...
It's the anti-siphon valve, 'n it might need cleanin'...
Don't throw it away, it's Necessary...

 

[kyhemi57]

Re: Gas?- PLEASE HELP!!!!

Dumb question, how do I find that?

 

[Bondo]

Re: Gas?- PLEASE HELP!!!!

Dumb question, how do I find that?

Ayuh,.... Follow the fuel line towards the bow,...
You'll run into the tank eventually...

Are there any access hatches in yer deck anywhere,..??
Under a seat,..??
Look at the fill hose, 'n see which direction it runs...

 

[jimbo_jwc]

Re: Gas?- PLEASE HELP!!!!

Hose bib screwed into antisiphon valve at tank 90Degree fitting on top full fuel line when pumped with pressure opens and closes with each fuel pump or primer bulb squeese to get fuel to pump then carb.

 

[stonyloam]

Re: Gas?- PLEASE HELP!!!!

Im assuming it should be gravity fed and gas should freely flow out of the tank through this line to the fuel pump, right?

That is exactly what you DO NOT want to happen. If that were the case, if the line were cut all of the fuel would drain into the bilge, not a good thing. The tank is designed so that the fittings are on the top with a tube going straight down to the bottom of the tank. Here is a cutaway view (best that I could find) http://www.moellermarine.com/oem/fuel_tanks/ . In addition there is an anti siphon valve on the fitting that prevents fuel from siphoning out of the tank if the line going to the pump is cut below the fuel level of the tank. This is a ball valve with a spring keeping it closed unless the fuel pump pulls the fuel through. So if you have fuel in the tank and the pump is drawing but you can not pump fuel out of the tank I would speculate 1 of two things: Either the ball in the valve is stuck (can't draw anything through) or the tube has come disconnected from the bottom of the fitting (you draw air through but no fuel). Good luck.