#Testing fuel pump driver module full

For naturally aspirated engines, estimate the BSFC to be 0.4 to 0.5.BSFC can be estimated but for best results, the actual number measured on a Dyno should be used. BSFC is usually a number between 0.4 and 0.7 for gasoline engines. brake horsepower) is measured at the flywheel, NOT at the rear wheels. BSFC (Brake Specific Fuel Consumption) represents how much fuel (in-lb) required per hour per each brake horsepower the engine produces. Requires module tuning for fuel pressure changeĬan I Swap Between Return and Return-less Systems?Įngine Horsepower (a.k.a.Fuel is always pressurized even when the engine is off.No return line (hence returnless), less line, less weight and fuel line cost.More technological and modern when compared to the return style system.There is no return line from the fuel rails back to the tank. A PPRV (Positive Pressure Relief Valve) which is implemented to maintain the pressure in the system when you turn the car off, which allows for easy start-ups and it also prevents excessive pressure in the lines. 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. Requires more fuel lines, more lines, more potential leaks.Simpler system when compared to the average returnless style.Since the fuel is constantly cycling through the system, it’s always there ready to be used as opposed to a returnless system that takes a couple things into account before sending fuel. Return systems are more beneficial in big horsepower applications where there is a high demand for fuel. This style system is constantly flowing, which means your fuel pump(s) are constantly operating at 100% duty cycle. Now with return style, there is a return line that takes the excess, or unused, fuel back to the tank and the cycle is continuous. Most enthusiasts replaced the regulator with an adjustable aftermarket product so they can tune their fuel system to the desired fuel pressure. The pressure is monitored by a fuel pressure regulator or FPR. From the tank, there is a feed line that runs through the fuel filter and up to the fuel rails, which supplies the injectors with fuel. The return style fuel system, used in the pushrod 5.0L and early 4.6L motors, uses a traditional in-tank pump just like the returnless style.

#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. 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.