Fuel Problem

[txflood]

I have a boat with a 1996 Volvo Penta 4.3GS that I'm having troubles getting started. It does have gas in the tank.

After reading this thread, I had some questions I was hoping someone could help me with.

It doesn't seem to be getting any gas up to the carb in my case and one thing I didn't check is to make sure the fuel filter was completely full of gas. I was wondering then if these type of fuel pumps can't self-prime and it is required for the fuel filter/separator to be full.

I have attached a pic showing the way the fuel pump is mounted on this engine. You can't see it but the black circle below the pump is where the filter mounts. The pump is basically drawing straight up out of that filter.



The other thing that I tried during my short investigation the other day was detaching the hose going down to the tank. I opened the fuel cap and then blew air down the fuel line hose going to the tank with my air compressor just in case of a blockage that way. I did hear bubbles in the tank, but the fuel line hose was quite rigid, lots of pressure to get that air in there. I don't know much about boat fuel tanks other than its a vent system, so does that seem normal?

Thanks

 

[Don S]

Re: Fuel Problem

Are you sure the fuel pump is working?

Here is a thread for testing the fuel pump electrically. http://forums.iboats.com/showthread.php?p=2715541#post2715541

You also need to check the fuel pressure to see if the pump is actually making pressure.

The fuel filter may not always be full, but it should fill back up if the pump is running. Just looking at things doesn't mean anything, unless you know what you are looking at.

The reason for resistance in the fuel line when you tried to blow through it is due to the anti siphon valve installed in the top of the pickup tube of the fuel tank.

 

[txflood]

Re: Fuel Problem

I've been meaning to reply here and finish the rest of the story of what I found. In short I ended up replacing the fuel pump, but at first could still not get the boat to start. I had also replaced the fuel filter with a new one and did not fill it up with gas. After taking the filter off and making sure it was totally full of gas and putting it back, the boat started up after a couple of tries.

So my conclusion is that yes, this model of engine really does require the fuel filter to be topped off or close to it before it will start. Not a great design in my opinion but it does seem to be the case.

Thanks for the help and the tips!