Link Search Menu Expand Document

Fuel Pump Priming

This ECU is peculiar in that it does not want to turn on the fuel pump until it see’s a crank signal. That means the engine cranks for just a little longer than I’d like. I’d much prefer the pump to prime the fuel rail before I crank. The fix is to install a momentary relay to give the fuel pump power when you turn ignition on. Believe it or not, such a relay is harder to find than you might think. However, Car Builder Solutions sell a 0-60 second timer relay which will engage for a short time when it’s given power. This means we can use it to supply power to the fuel pump for 3-5 seconds when we first turn on the ignition. The fuel rail will then have fuel pressure so the engine fires quickly, then the ECU will turn the fuel pump on to maintain pressure.