Fuel Injectors: Stock Mustang Fuel Pressure Rating

Fuel injectors are a vital part of a Mustang's engine, supplying it with the correct amount of fuel. Fuel injectors are rated and distinguished by the rate at which they flow fuel, which is usually rated in either cc's (cubic centimeters) or pounds, measured over time (i.e. 39 lb/hr). The fuel pressure can be dictated by the voltage sent to the pump via the PCM (powertrain control module). The stock fuel pressure for a Mustang varies depending on the model year and engine type. For example, the stock fuel pressure for a 1990 GT with a 2.73 gear is 44 psi, while the stock fuel pressure for a 2015+ Mustang V6 is 29 psi.

Fuel injectors deliver fuel from the lines into the engine

Fuel injectors are a vital part of a car's engine, delivering fuel from the lines into the engine so that the car can run.

In the 1990s, the carburettor was replaced by fuel injection, a system that could meet tough new emissions standards and boost the engine's performance. Fuel injection is the primary means of getting gasoline into the engine cylinder so that it can combust and the car can be driven.

The fuel supply module sends fuel under pressure to the injectors, one per cylinder. The quantity of fuel that reaches the injector is precisely controlled by an ECU, which considers air temperature, throttle position, engine speed, engine torque and exhaust data gathered from sensors in and around the engine to regulate the supply at each intake stroke.

Air arrives via the intake manifold and is drawn into the engine past the intake valve or valves. The fuel and air are then introduced to each other and mixed, but how this happens depends on the type of fuel injection system being used.

Most petrol engines use an indirect fuel injection system, where the fuel is injected into the intake manifold, the arrangement of pipes that channel the incoming air to the engine. Here, the fuel and air are mixed before being drawn into the combustion chamber.

In a direct fuel injection system, such as those used by diesel engines and, increasingly, petrol engines, the fuel is sprayed directly into the combustion chamber under extremely high pressure and directly into the incoming air stream.

A fuel injector atomises the fuel by forcibly pumping it through a small nozzle under high pressure into the combustion chamber, where it is ignited. This atomisation allows the fuel to burn more completely, releasing all its potential energy, which translates into better fuel economy and more power.

The flow rate of a fuel injector is measured in pounds per hour and is available in different sizes depending on the application.

Stock Mustang fuel injectors are rated at between 19 and 32 pounds per hour, depending on the model year.

Fuel injectors are rated and distinguished by the rate at which they flow fuel

The flow rate of a fuel injector is the amount of fuel it can spray into a combustion chamber. It is vehicle and engine-specific and is determined by the engine manufacturer, who programs the flow rates into the electronic control unit (ECU). The ECU then uses these values to determine how many pulses need to be sent to each injector to achieve the desired level of fuel delivery.

The flow rate is important because it ensures the correct fuel-to-air ratio and, when correct, results in OEM-spec performance. If the flow rate is incorrect, issues such as poor fuel economy and engine damage can occur.

When replacing fuel injectors, it is important to get ones that have the same flow rate as the stock injectors, unless the engine has been modified to increase performance beyond factory limits. In this case, injectors with a higher flow rate are required.

Fuel injectors come in different body styles: EV1, EV6, and EV14. The EV1 and EV6 injectors are commonly referred to as "long", while the EV14 is known as "medium".

The size of a fuel injector is not determined by its physical dimensions but by its flow rate. The flow rate is influenced by the fuel injector's physical size, among other factors.

The formula for calculating the correct size fuel injector for a Mustang is:

> Injector Flow Rate (lb/hr) = (Engine HP) x (BSFC) / (Number of Injectors) x (Injector Duty Cycle)

The fuel injectors in a Mustang are responsible for injecting fuel into the engine. They do this by forcibly pumping the fuel through a small nozzle under high pressure into the combustion chamber, where it is ignited. This process, known as atomization, allows the fuel to burn more completely, resulting in better fuel economy and more power.

The stock Mustang fuel injectors have different flow rates depending on the model year. For example, the 1986 model had 19lb/hr injectors, while the 2005 model had 24 lb/hr injectors. The 2011 model had 32 lb/hr injectors, and the 2018-2021 models have 34 lb/hr injectors.

Fuel injectors are measured in either cc's or pounds

Fuel injectors are a vital part of your Mustang's engine, supplying it with the correct amount of fuel. They do this by forcibly pumping fuel through a small nozzle under high pressure into the combustion chamber, where the fuel is ignited.

When it comes to choosing a fuel injector, there are a few key measurements to consider. Firstly, fuel injectors are measured in either pounds per hour (lb/hr) or cubic centimeters per minute (cc/min). When someone says "a thousand cc injector", they mean 1000cc/min, or 96lb/hr. Likewise, "I need 210's" means 210lb/hr, or 2200cc/min.

The standard fuel pressure for injectors is 43 psi/3 bar, and all injectors are rated to deliver a specific amount of fuel at this pressure. For example, a Holley injector rated at 42lb/hr will deliver 42 pounds of fuel per hour at 43 psi.

It's important to choose the right size of the injector for your engine, and this will depend on your horsepower goal. As a rule of thumb, when sizing your injector for gasoline, you will need 1cc/min flow for each horsepower. So, if you want to make 1000 crank horsepower on 93 octane gasoline, using a fuel pressure of 43 psi, you will need a 1000cc injector.

You can also use a formula to calculate the correct size of the injector: Injector Flow Rate (lb/hr) = (Engine HP) x (BSFC) / (Number of Injectors) x (Injector Duty Cycle). BSFC, or Brake Specific Fuel Consumption, represents the amount of fuel consumed (in lbs per hour) for each horsepower made. For naturally aspirated engines, this will be between .45 and .50, for supercharged engines, .55 to .60, and for turbocharged engines, .60 to .65.

It's worth noting that bigger is not always better when it comes to fuel injectors. Upgrading to a larger size than you need can cause your engine to run rich, resulting in a loss of power.

In summary, when choosing a fuel injector, consider your horsepower goal and the type of fuel you will be using, as well as the injector's measurements in either ccs or pounds, to ensure you select the correct size for your Mustang's engine.

A bigger fuel injector will allow your Mustang to make more power

Installing bigger fuel injectors in your Mustang will allow more fuel to enter the engine, which can result in more power being generated. However, it is important to note that simply installing larger fuel injectors will likely cause engine problems. This is because the larger injectors will be supplying more fuel than the engine can handle without other modifications.

To take full advantage of the extra fuel supplied by bigger fuel injectors, you will need to make additional upgrades to your Mustang. Here are some of the key modifications that are recommended alongside installing larger fuel injectors:

• Upgrade your fuel pump: A bigger fuel injector will require a more powerful fuel pump to deliver the extra fuel.
• Increase the size of your fuel lines: The fuel lines need to be large enough in diameter to handle the increased volume of fuel supplied by the larger injectors.
• Install a bigger throttle body: A bigger throttle body will be needed to control the increased airflow into the engine.
• Upgrade the intake and exhaust system: Improving the intake and exhaust system will help the engine breathe better and make more power.
• Add forced induction: Adding a supercharger or turbocharger will increase the airflow into the engine, making more power possible.

It is also important to note that bigger fuel injectors may require a tune to work properly. This is because the increased fuel flow can throw off the air-fuel ratio, and a tune can help ensure the correct amount of fuel is being delivered.

In summary, while bigger fuel injectors can allow your Mustang to make more power, it is essential to make the necessary upgrades and modifications to the fuel delivery and engine management systems to handle the increased fuel supply and avoid potential engine problems.

Fuel injectors are considered the main part of your fuel system

The fuel injection process helps deliver maximum power while minimising fuel consumption and reducing pollution. It achieves this by producing a finer fuel droplet spray that burns more efficiently. Modern fuel injectors are electronically controlled valves that are supplied with pressurised fuel by the fuel pump in your car. They are capable of opening and closing multiple times per second.

The amount of fuel supplied to the engine is determined by the amount of time the fuel injector stays open, known as the pulse width. The pulse width is controlled by the ECU, which uses data from various sensors to fine-tune fuel consumption and delivery. These sensors include the mass airflow sensor, oxygen sensor, throttle position sensor, coolant temperature sensor, voltage sensor, manifold absolute pressure sensor, and engine speed sensor.

The fuel injectors are typically made of stainless steel and have a plunger or valve that opens and closes to control fuel flow. The injector body converts the electrical signal from the solenoid into pressure to push the fuel through the nozzle. When triggered, the solenoid opens, allowing fuel to flow through the nozzle and into the engine's combustion chamber.

In summary, fuel injectors play a critical role in the fuel system by regulating fuel injection, optimising combustion, and reducing emissions and fuel consumption. They work in conjunction with the ECU and various sensors to ensure efficient and effective fuel delivery to the engine.

Frequently asked questions