Finny Inline Fuel Pump Testing

[joey.dale]

I have an Inline gas fuel pump from a 61 300se. Is there any way for me to test it to confirm it works? If so please explain.

Thank You
-Joey

[ja17]

Hello,

Hook 12 volt DC power to the terminals. If it runs it is most likely good. Do not run it long. Be careful no fuel is around or a spark can ignite it.

These pumps are gravity feed and must hang lower than the fuel supply. They are high volume (one liter every 15 seconds) and can produce around 40 psi max fuel pressure, although designed running pressure is around 14 psi when installed in a system with an open return fuel line to the tank.

Often times the pumps can get stuck from inactivity. If you can get the little slotted screws of the bottom of the pump and open it up you can most likely clean it out and work it free again.

This style electric fuel pump under went some changes over the years so there were several versions used, starting from models with the mechanicallly injected engines in the Pontons, Finbacks, and W108 models. Finnally a much smaller and simpler version with the same specs was used in the EFI injected W116 cars and the W107 SLs. Later CIS engines, used and different electric fuel pump with a much much higher fuel pressure but similar function.

Rember, they were meant to be gravity feed and should hang as low or lower than the fuel supply or you will have problems.