filter on fuel pump?

On my 1991, 3.0 liter mercruiser, I was looking at part # GLM77115 on ebasic power -- says this is the replacement fuel pump that I need. It says in the description that it is a new style Carter Pump with the filter on the bottom of the pump.

I had no idea that there was a fuel filter in the bottom of the fuel pump. Does this thing get clogged? I'm wondering if this could be why my fuel pump has been acting funny and sometimes stops pumping gas.

Anyone have any experience with these things? I was going to just replace it, but maybe there is something else to it.

(by the way, sometimes my carb does get gas at low rpm's. I know that the typical failure of fuel pumps is at higher rpms, but I've changed the the water separator and the fuel isn't making it to the inline fuel filter, so I'm thinking it is the pump)

Re: filter on fuel pump?

1st thing I usually do for this type of thing is try to run it on a small portable outboard fuel tank and see if the problem goes away. If it does the problem is towards the boat side of the fuel system if not the it's motor side of the fuel system.

James

Re: filter on fuel pump?

He could do that (the prtable fuel tank thing) but IF he does have a filter on the bottom of the fuel pump and IF it is grossly plugged the portable tank will do nothing. I would get the portable tank out after checking all the fuel filters especially if they haven't been looked at in a while.

I have an 89 3.0L and there is a small filter on the bottom of the fuel pump. When you remove it, it will look like some kind of porous stone or something. But being a filter I would imagine it would be totally possible to plug.

If I'm not mistaken, if a mechanical marine fuel pump fails you should see fuel in the yellow hose that goes from the fuel pump up to the carb. That would be if the diafragm fails. Anything can happen but my experience with fuel pump failures is that your engine might idle well or even run in gear with a slight load but that will be about it.
Oh, don't forget to check the filter in the fuel inlet at the carb.

Good luck

Re: filter on fuel pump?

TyeeMan said:

If I'm not mistaken, if a mechanical marine fuel pump fails you should see fuel in the yellow hose that goes from the fuel pump up to the carb. That would be if the diafragm fails. Anything can happen but my experience with fuel pump failures is that your engine might idle well or even run in gear with a slight load but that will be about it.
Oh, don't forget to check the filter in the fuel inlet at the carb.

Good luck

Click to expand...

Fuel in that line is often the case but we had a fuel pump go bad last summer and there wasnt any fuel in that line. We opened the pump up and there was some small cracks in the diaphragm but nothing major. Maybe it needs a rather large tear or hole for that to happen??

Either way, if you do use a portable gas can and it still does it then that rules our the tank on your boat. You should look into replacing those filters if they do exist though.

Re: filter on fuel pump?

Thank you for your resposes. So that I could test this, I put a glass fuel filter inline before the carb...and gas isn't getting to the carb, so it's not the filter that is before the carb.

i'd just never known that there was that filter under the fuel pump and was wondering if anyone had ever had one clog.

Oh - the tank is venting properly, I checked that a bit ago.

Re: filter on fuel pump?

It's not just the tank venting that can cause a problem on the boat side of the fuel system. You could have a clogged or bad anti syphon valve. You could have a tank pickup with a hole near the top allowing air to be sucked into the fuel system. You could have a fuel line that has an inner layer "delaminating" and sucking closed under vacume from the fuel pump.

James