#Testing fuel pump driver module driver
These systems also use an FPDM (Fuel Pump Driver Module), which is an electrical device designed to keep the desired pressure at the injectors and controls the power sent to the fuel pump. In a returnless system, the fuel pump is not operating at 100% of its duty cycle. The fuel pressure is controlled by the amount of voltage being sent to the pump and other electronics. Returnless fuel systems are quite different and can be complicated.
#Testing fuel pump driver module full
Most aftermarket adjustable regulators are also one-to-one or close to that, however you have the ability to adjust the pressure at idle or full throttle for fine tuning.
![testing fuel pump driver module testing fuel pump driver module](https://ecat.spectrapremium.com/img/produits/TB1232_TOP_P04.jpg)
In factory regulators, for every pound of boost, it adds a pound of fuel psi since it has a one-to-one ratio. If you add more positive manifold pressure to your system with turbo or supercharger, the added boost pressure will further increase fuel pressure. At full throttle, the engine is in a no vacuum situation, in theory it would be 0psi to standard manifold pressure ratio. It also utilizes an internal diaphragm to control the pressure.Īt idle, the engine is in a manifold vacuum situation and the fuel pressure is around -9psi to manifold pressure ratio. It varies the fuel pressure by being connected to manifold pressure via a vacuum connection. Your Mustang, as well as most fuel injected cars, has a one-to-one ratio fuel regulator. The pressure in the fuel rail and intake manifold should be maintained at a level to suit the optimum air/fuel ratio. The fuel pressure regulator, fuel rails and fuel injectors make up a system that delivers the correct amount of fuel to each cylinder for proper combustion.