nbrskn

Pump went bad. Replaced pump then had a [clacking noise ? ] Put listening device on pump. Noise is from fuel pump. Put on another new pump and still have same noise. Seemed tight against the cam esentric. Any suggestions ?

Martian

Good pressure? Might be noisy because it's not receiving adequate power.

nbrskn

more info 1978 460 mechanical pump

GhostriderI

Are you sure you got the arm under the cam? Just a thought

nbrskn

pumps gas real well. Anything else it could be under?

GhostriderI

I have seen pumps work with the arm over the cam as good as under. They break faster because of the stress on the arm and linkage. With that said, the new pump could just be stiff and the arm is not tracking with the cam as it rotates thus losing contact and tapping as it returns to the cam. Also since that is a splash lube area could be some "trash" keeping it from getting oil. If you can easily, drop the pump, see if it is wet with oil, if not lube the arm and pivot points with oil, reinstall, if noise goes away that was/is your problem.

Hope this helps

nbrskn

if the arm is over whats going to push the arm down ?

GhostriderI

The diaphram will pull it back until it breaks or the rod bends whichever comes first.

Johnboy429bbf

More then likely if the pump arm is non top the esentric your see wear on the bottom of the are. Also make sure the fuel is flowing free of restrictions from the pump to the carb. Manly the fuel filter

nbrskn

yes you would see wear on bottom of arm . cam would push arm up on high side of cam but then what would push arm down on low side of arm? no push down no pumping of gas. Diaphram might push arm up but its not going to pull it down. Spring in pump will keep it up until cam pushes it down