S&B Fuel Sending Units

Tech note for customers and installers

Question:

Can the sending unit draw fuel from the venturi port if the lift pump fails or the filters are clogged?

Answer:

The venturi pump nozzle has an orifice size of approximately 0.02 inches in diameter. A mesh screen is installed ahead of the nozzle to help prevent debris from clogging the small opening.

If the lift (FASS) pump fails: the engine may briefly enter limp mode while trying to pull fuel through the 0.02-inch nozzle and mesh screen. In most cases, the vehicle will not be drivable because sufficient fuel cannot be drawn through that small passage.

For compatible options, visit our Fuel Sending Units product page .