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Q: Rough start/idle plus loss of power

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The car is experiencing hard start only when it's cold and from time to time it had rough idle which gets rougher when the car is in gear. I've replaced fuel and air filters. Also car has loss of power when I punch it. I ran diagnostics and the car. Some back with whole bunch of codes for miss fires P0300-P0306, fuel pressure regulator performance P2293. I might also add I'm terrible at maintaining the car and have a oil leak :(((

My car has 125000 miles.
My car has an automatic transmission.

Hi There, This is an indication of a fuel pressure problem as indicated by the codes you have pulled. The fuel pressure regulator is a device which controls the pressure of fuel supplied to the fuel injectors on an engine. This works by bleeding off a portion of the fuel flow to the injectors from the fuel pump to control the fuel pressure. Fuel is pumped from the fuel tank to the fuel rail by the fuel pump. The fuel pressure regulator is normally mounted after the fuel rail to ensure that the fuel rail has priority in fuel flow. The valve in the regulator controls the amount of fuel that is bled from the fuel rail by opening an outlet port to allow fuel to flow back into the fuel tank. All injectors need a pressure difference between the inlet and the outlet of the injector to spray fuel into the combustion chamber. This is called the base pressure. The base pressure is adjusted via the adjustment screw to suit the injectors and specific fuel pump system you are using. The adjustment screw pushes down on a spring which applies a force onto the valve. When the pressure inside the bottom chamber of the regulator exerts a high enough force on the valve to overcome the spring force and lift the valve off its seat, it allows fuel to flow through the outlet port effectively controlling the fuel pressure in the fuel rail. Since the outlet of the injector is exposed to manifold vacuum/pressure which varies depending on throttle movement, but the flow of fuel from the fuel pump is constant, the valve needs a reference to continuously change the amount of fuel bled to maintain constant fuel pressure to the injectors. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

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