Fuel pump running dry

[SeattleMatt]

1998 Volvo Penta SX 4.3. Motor died and I diagnosed as not getting fuel. I followed Don's troubleshooting steps. I can see the fuel pump runs when jumpered, but no fuel comes out.

-Checked the filter and emptied it, but didn't seem to be dirty, I had recently replaced it.
-Checked the feed line to the filter housing, i was able to suck fuel from the tank
-removed the line from pump to carb and no fuel comes out when pump is running. You can feel a little bit of air flowing there.

 

[SeattleMatt]

I have a problem with fuel pump on 1998 Volvo Penta SX 4.3. Motor died and I diagnosed as not getting fuel. I followed Don's troubleshooting steps. I can see the fuel pump runs when jumpered, but no fuel comes out.

-Checked the filter and emptied it, but didn't seem to be dirty, I had recently replaced it.
-Checked the feed line to the filter housing, i was able to suck fuel from the tank
-removed the line from pump to carb and no fuel comes out when pump is running. You can feel a little bit of air flowing there.

 

[alldodge]

Checked the filter and emptied it, but didn't seem to be dirty, I had recently replaced it.

Suggest placing the fuel line coming from the filter to tank, in a gas can and see if the pump will pump fuel. If it does then its the tank and fittings

 

[SeattleMatt]

Sorry for the double post....:|

 

[bruceb58]

I would be doing a test with the input of the pump being fed by a remote fuel tank.

Be very careful doing these types of tests so that the spark created when you operate the pump doesn't ignite gas fumes.

 

[SeattleMatt]

Resolved. I ended up removing the pump entirely and testing it with and without liquid, I used water to be safe. As it turns out the pump will not pump without liquid primed in it. So I re-assembled and filled the filter to the brim with gas and spun it on, then ran the pump again and saw that it started pumping fuel.

All is working now. However I have concerns.

1. When I replaced the filter before I didn't have any issues using an empty filter.
2. What caused this? How could the pump end up this way. I'm guessing it was the filter plugged up and I just didn't prime it right when reattaching.

 

[SeattleMatt]

Well, the next morning the problem recurred.
This time I pulled the filter off, it was about an inch low on fuel. filled it to the brim, spun it back on and got it going.

Any ideas what is going on here?

Real question is, does the fuel pump need to be primed with a full filter to work? If not there is some reason the fuel pump is only working with a fully primed fuel filter.

The boat did just move to Montana with a much higher elevation than it was previously, I'm sure this is related somehow, but not sure how.

 

[dypcdiver]

Check the fuel tank vent, and the anti syphon valve if it has one. Could be the fuel is flowing back to the tank, make sure that all the pipework to the pump is secure and with no leaks, as it could be sucking air at a fitting or cracked hose.

 

[bruceb58]

I could use similar help. I have been playing with mine for sometime, and it looks like the anti-siphon was not preventing the fuel from draining back into the tank. I changed the Anit-siphon valve, but still concerned what is the line is dry. My fuel pump does not come on with the key, but does come on with the ignition. Is there something wrong with my relay or one of the diodes?

4,3GL Volvo penta

You should start your own thread.

On a GL, since its a carb, it will only come on while cranking or running. By running, it means the alternator is putting out a voltage on it's L2 terminal to energize the relay.

 

[SeattleMatt]

Is it possible that the fuel pump is going out causing it not to be able to prime itself?