3.0 mercruiser fuel pump questions

[Jamz3333]

I have a 1988 baretta that I think the fuel pump has went out on. I would keep putting gas in the carburetor thinking the pump just needed some help picking up the gas. Well it didn't help because I still never got it to start. I took off the inlet side of the pump and the gas line was dry. Is there anyway of telling if the pump is bad before taking it off? Thanks for the help!

 

[eavega]

Re: 3.0 mercruiser fuel pump questions

Isn't the sight tube running from the top of the pump to the carburetor supposed to indicate the pump is bad if it is full of fuel?

-Rgds

 

[ktbarrentine]

Re: 3.0 mercruiser fuel pump questions

The sight tube will tell you if the fuel pump diaphram is leaking by.... (cracked/torn, etc.) That is only one cause of a bad fuel pump. There are others, like a broken diaphram rod, bad pump valves (i've experienced all of these at one time or another).... Problem may also not be in the pump, but may be upstream.

 

[Bondo]

Re: 3.0 mercruiser fuel pump questions

I have a 1988 baretta that I think the fuel pump has went out on. I would keep putting gas in the carburetor thinking the pump just needed some help picking up the gas. Well it didn't help because I still never got it to start. I took off the inlet side of the pump and the gas line was dry. Is there anyway of telling if the pump is bad before taking it off? Thanks for the help!

Ayuh,..... Kt is Right,... Plumb in a remote tank to the fuel pump, 'n Try it...

The tank may not be givin' up it's fuel....

 

[Jamz3333]

Re: 3.0 mercruiser fuel pump questions

Ayuh,..... Kt is Right,... Plumb in a remote tank to the fuel pump, 'n Try it...

The tank may not be givin' up it's fuel....[/QUOTE
Could I just take a jug of gas and run a hose into it?

 

[Silvertip]

Re: 3.0 mercruiser fuel pump questions

A stuck anti-siphon valve where the fuel line hooks to the tank is suspect as well.

 

[Jamz3333]

Re: 3.0 mercruiser fuel pump questions

Also why wouldn't the tank give up its fuel? And a fuel pump that worked when the boat was parked in the fall, just go bad while sitting?

 

[dubs283]

Re: 3.0 mercruiser fuel pump questions

Also why wouldn't the tank give up its fuel? And a fuel pump that worked when the boat was parked in the fall, just go bad while sitting?

stuck anti-siphon valve, plugged or broken pick-up tube, plugged vent hose, etc...

maybe the pump was weak last fall and sitting over the winter the diphragm dried out and broke?? any number of reasons why mechanical items fail

 

[Jamz3333]

Re: 3.0 mercruiser fuel pump questions

I didn't try the external tank idea but I took the pump off and I could not blow back through the tank. Is this normal? The I.D. on the pump says mo-2393. It is a carter pump. What other brand of pumps will fit my motor? I just haven't found much luck by searching the I.D. online.

 

[Bt Doctur]

Re: 3.0 mercruiser fuel pump questions

I didn't try the external tank idea but I took the pump off and I could not blow back through the tank. Is this normal?

Yes, the anti-syphon is a spring loaded one way valve.fuel needs to be sucked out.

Also why wouldn't the tank give up its fuel? And a fuel pump that worked when the boat was parked in the fall, just go bad while sitting?

stuck anti-syphon valve, weak fuel pump. do the remote tank test and let us know the results .