Finding The Fuel Pressure Regulator In Mk2 Celica Supras

The fuel pressure regulator in the Toyota Celica Supra MK2 is an essential component of the fuel system, ensuring that fuel pressure is appropriately regulated for optimal engine performance. Located within the fuel delivery system, the regulator controls the pressure of fuel as it travels from the tank to the engine, maintaining a consistent flow. This mechanism is crucial for the vehicle's overall drivability, fuel efficiency, and engine lifespan. When the fuel pressure regulator malfunctions, it can lead to a range of issues, from hard starting and stalling to poor throttle response and reduced engine power. Diagnosing and replacing a faulty fuel pressure regulator is a complex task that requires careful inspection of the fuel system and consideration of other potential causes.

Fuel pressure regulator symptoms

The fuel pressure regulator plays a crucial role in maintaining the desired fuel pressure in your Toyota Celica Supra. When it goes bad, you may experience various symptoms that indicate a faulty regulator. Here are some common symptoms of a failing fuel pressure regulator:

• Engine Performance Issues: A bad fuel pressure regulator can cause a loss of fuel pressure, leading to engine performance problems. You may experience hard starting, where the engine takes longer to start, stalling, rough running, and a lack of power.
• Check Engine Light: The check engine light illuminates when the engine computer detects issues that can increase emissions. A faulty fuel pressure regulator can trigger the check engine light, along with storing a diagnostic trouble code (DTC) in the computer's memory.
• Black Smoke from the Tailpipe: A malfunctioning fuel pressure regulator can cause the engine to run rich, resulting in excessive fuel consumption and black smoke coming out of the tailpipe.
• Fuel in the Regulator's Vacuum Line: In some cases, a ruptured diaphragm inside the regulator can lead to fuel leaking into the vacuum line. This can be a clear indication of a faulty regulator.
• Vehicle Cranks but Doesn't Start: A faulty regulator can disrupt the proper fuel pressure supply to the engine, resulting in a situation where the vehicle cranks but fails to start.

It's important to note that these symptoms may also be caused by other issues, so it's always recommended to consult a professional mechanic for a thorough diagnosis. Additionally, modern vehicles with returnless fuel systems may not exhibit the same symptoms as they don't have external fuel pressure regulators.

Fuel pump relay

The fuel pump relay in a Toyota Celica Supra MK2 is located in two places. The first is the Main Relay #1, which can be found in the fuse block in the engine bay. The second is the Circuit Opening Relay, which is located behind the driver's side kick panel. To access the Circuit Opening Relay, you need to remove the kick panel. It will be the green relay in the bottom right corner. There is a 10mm bolt above it that the mount connects to.

The fuel pump in the Toyota Celica Supra is located externally, in front of the fuel tank. It sits towards the front of the car.

Fuel pump upgrade

The fuel pump in the Toyota Celica Supra is located in the fuel tank, on the passenger side of the vehicle, near the rear of the car. The fuel pump is external for the 82 model, but internal for the 83 model.

Upgrading the fuel pump in your MK2 Celica Supra can improve performance and fuel efficiency. When choosing a replacement fuel pump, it is important to consider the flow rate, voltage, and compatibility with your vehicle.

You can opt for a higher-flowing pump, which can be beneficial for future upgrades. For example, you could consider a Walbro 255 fuel pump, which offers a balance between performance and cost. This pump can be purchased online or from specialist auto parts stores.

If you are on a budget, you may consider sourcing a used fuel pump from a junkyard. Fuel pumps from the MK3, MK3 Turbo, Lexus SC300, or SC400 models will fit directly into the MK2 Celica Supra with no wiring or fitment issues.

When upgrading your fuel pump, it is also recommended to replace the fuel filter and the sock/screen filter inside the fuel tank. A clogged filter can cause similar issues to a faulty fuel pump, such as hard starting and stalling.

Additionally, you may want to consider upgrading your fuel pressure regulator to a fully adjustable unit. This will allow you to fine-tune your fuel pressure for optimal performance. Adjustable fuel pressure regulators are available from specialist automotive performance retailers and typically come with vehicle-specific fitting kits.

Finally, always refer to a qualified mechanic or a factory service manual for detailed instructions on how to safely remove and install a fuel pump in your vehicle.

Rising rate fuel pressure regulator

The fuel pressure regulator in the Toyota Supra Mk2 is an important component of the fuel system, ensuring that the engine receives the correct amount of fuel at the right pressure. A faulty fuel pressure regulator can cause various issues, such as hard starting, choking, and stalling.

Now, let's discuss the concept of a rising rate fuel pressure regulator in detail.

A rising rate fuel pressure regulator is a type of fuel pressure regulator that increases the fuel pressure in relation to the boost pressure. This means that as the boost pressure increases, the fuel pressure is also raised to maintain the optimal fuel flow and prevent the air pressure from affecting the fuel delivery. The ratio of this increase is often 1.7:1 or 1.5:1, which means that for every 1 psi of boost, the fuel pressure is increased by 1.5 or 1.7 psi, respectively. This results in a richer fuel mixture, which can be beneficial for performance.

The benefit of a rising rate fuel pressure regulator is that it can compensate for a fuel system that is slightly undersized or not perfectly matched to the setup. It is particularly useful for low-pressure boosting applications in naturally aspirated cars. Additionally, it can provide some fuel enrichment, which is useful when the fuel mapping is not perfectly tuned for higher boost levels.

However, it's important to note that the rising rate fuel pressure regulator is not a substitute for proper tuning. The enrichment it provides has diminishing returns, as doubling the fuel flow requires squaring the pressure, not just doubling it. Therefore, while it can be beneficial for low to medium boost applications, it may not be sufficient for very high boost levels.

In the case of the Toyota Supra Mk2, a rising rate fuel pressure regulator can be considered, especially if the fuel system is not perfectly matched to the setup. However, it is important to ensure that the fuel pump can deliver the required fuel flow at the elevated pressures. Additionally, proper tuning through an ECU (Engine Control Unit) is still essential to achieve the best performance and fuel enrichment.

Fuel pump fuse

The fuel pump relay is an essential component for the combustion engine to function. When the ignition is turned on, the fuel pump relay supplies electricity to the fuel pump. When the ignition is shut off, the fuel pump relay powers down the fuel pump.

The fuel pump relay can often be found in the fuse box in the engine bay, which is usually a long black box that contains the relay along with various other fuses and relays. However, the location of the fuel pump relay can vary depending on the car model. It may be found under the hood, on the firewall, or near the steering column.

To locate the fuel pump fuse, follow these steps:

• Raise the hood of your car and look near the battery for a black, plastic box.
• Unsnap the lid and raise the cover. On the inside of the lid, there should be a schematic of the fuse orientation.
• Inside the box, you will find an array of circuit breakers, fuses, and relays arranged according to the schematic.
• One of the small, black relays is likely to control the fuel pump. Near the relay, there is typically a red, 10-amp fuse labeled "FUEL," "F/P," or "FUEL PUMP."
• If the fuel pump fuse is not in the power distribution box, check under the dashboard. Use a flashlight to locate the fuse panel, which may be covered by a lower panel that can be removed with a small screwdriver.
• Remove the lid of the fuse panel and look for the same lettering that designates the fuel pump fuse.
• If the fuse is not there, look in the specialty fuse panels by checking another small, black electrical box with wires going into it, typically located in the engine bay or under the passenger side of the dash.
• Refer to the owner's manual to determine the specific location of the fuel pump fuse for your car model.

Frequently asked questions