Fuel Pressure Sensor: Is It Present In The 3000Gt?

The Mitsubishi 3000GT is a car model that has been in production since the early 1990s and has gone through several design iterations. While the car does have a fuel pressure sensor, there is no stock fuel pressure gauge, which can make it difficult to identify fuel pressure problems. This has been a common issue for owners of the 3000GT, with many forum posts discussing the best methods for checking fuel pressure and testing the fuel pressure sensor. Some common methods for checking fuel pressure include using a fuel pressure tester or gauge adapter kit, attaching a banjo fitting to the fuel filter outlet, and connecting to a gauge. It is also possible to bench test the fuel pressure sensor using a multimeter.

How to check fuel pressure

Checking the fuel pressure of your car can help you diagnose starting or running issues. Here is a step-by-step guide on how to do it:

Step 1: Check the Fuel Tank

First, make sure there is actually gas in the tank. Do not trust the fuel gauge, as it could be faulty. Add at least two gallons to the tank and try to start the car. If it starts, check the fuel gauge for internal failure and replace it if necessary.

Step 2: Verify the Fuel Pump Works

Go to the fuel tank and ask an assistant to turn the ignition switch to "On". You should be able to hear a two-second whir, hum, or series of rapid clicks as the fuel pump pressurizes the fuel line to the engine. If you don't hear any noise, the pump is either not getting power or it has failed. Check the fuel pump fuse and relay. If both are fine, check the wiring to the pump. If voltage is present when turned to "On", then the pump has failed.

Step 3: Prepare the Engine

With an entirely cold engine, pop the hood. Find a Schrader valve fitting on the fuel rail. Remove the Schrader valve cap and attach the appropriate fuel pressure tester fitting. Ensure it threads on properly for a leak-proof fit.

Step 4: Test the Fuel Pressure

Turn the ignition to "On", not "Start". Check the psi reading and wait. If the fuel pressure drops over 10 minutes (e.g. loses 20 psi in that time), there is a leak in the fuel system. Look for drips underneath to help locate the leak.

Then, start the engine and let it idle. You should see steady fuel pressure, within a few psi of the recommended pressure. Once warmed up, slowly rev the engine, making sure the pressure rises with the RPMs. If your fuel pressure holds steady, rises with engine speed, and is at the recommended pressure, then your engine problem does not seem fuel-related.

Step 5: Interpret the Fuel Pressure Readings

Zero fuel pressure means the pump is dead or not getting power. Check the fuel pump fuse and then verify power to the pump with a multimeter. If it's good, swap out the fuel pump.

Low fuel pressure could be due to a clogged fuel filter or a failing pump. If it is a serviceable type filter, replace the fuel filter. This could also be caused by improper tank venting or a loose gas cap. Check that the cap gasket isn't damaged, and tighten it until it clicks.

High fuel pressure could be caused by a clogged or kinked fuel return line, a bad fuel pump driver module, or a faulty fuel pressure regulator.

Fuel Pressure Testers for the Mitsubishi 3000GT

The Mitsubishi 3000GT does not have a test port, so you will need to purchase a fuel pressure gauge adapter kit. You can attach a banjo fitting with a longer banjo bolt to the fuel filter outlet and connect it to a gauge. Some pressure kits have these parts included.

Note: Fuel vapours are highly flammable, so ensure you perform these steps in a well-ventilated area with a fire extinguisher nearby.

Fuel pressure test

A fuel pressure test can be carried out to check for fuel pump malfunction, which can result in a lack of power output from the engine. A malfunctioning fuel pump is one of the most common causes of vehicle breakdown.

How to Test Fuel Pressure

Firstly, park your vehicle and apply the parking brake. Turn off the engine and allow it to cool down. Locate the fuel pressure test port and place a rag underneath it to catch any released fuel. Install the pressure tester to the port, turn on the ignition, and run the engine at a specific RPM. Check the pressure reading against the manufacturer's manual to see if it meets the required pressure specification.

There are several fuel pressure test kits available on the market. These include:

• Innova Fuel Injection Pressure Tester
• OEMTOOLS Fuel Pressure Test Kit
• ACTRON Ford Fuel Adapter for Fuel Pressure Tester Kit CP7818
• Mityvac Fuel Pressure Tester Kit
• OTC Fuel Pressure Testers 5630
• Summit Racing™ Fuel Pressure Tester Kits SUM-899002
• Nitrous Express Master Flo-Check Pro Gauge Kits 15529
• Powerbuilt Fuel Pump Diagnostic Kits 647959
• S&G Tool Aid Fuel Injection Pressure Gauges 58040
• S&G Tool Aid Fuel Injection Pressure Testers 33980
• Innova Fuel Pressure Gauges, Engine Diagnostic 3640
• S&G Tool Fuel Pressure Gauges, Engine Diagnostic 33936
• S&G Tool Fuel Pressure Gauges, Engine Diagnostic 33850
• S&G Tool Aid Fuel Injection Pressure Tester Gauges 33966
• Lang Tools Compuchek Fuel System Pressure Test Gauges TU-32-20

Fuel Pressure Sensors

Fuel pressure sensors can be tested using a multimeter. Probe the signal for 0psig, and either run the fuel system and probe for a voltage output that matches your base fuel pressure, or bench test with regulated air via a compressor.

Fuel pressure sensors

The Mitsubishi 3000GT does have a fuel pressure sensor. However, there is no stock fuel pressure gauge. This means that there is no port to check the fuel pressure.

One way to check the fuel pressure is to attach a banjo fitting with a longer banjo bolt to the fuel filter outlet and then connect to a gauge. Some pressure kits include these parts.

Another method is to attach a pressure tester from AutoZone inline after the FPR where the return line comes off.

If you want to install a fuel pressure gauge, you can buy a Defi Fuel Pressure Sensor and follow the installation instructions.

Fuel pressure gauge

The Mitsubishi 3000GT does not have a stock fuel pressure gauge. However, you can install an aftermarket fuel pressure sensor and gauge to monitor fuel pressure. This is important for tuning your engine and diagnosing fuel system issues.

To check the fuel pressure on a Mitsubishi 3000GT, you will need to purchase or rent a fuel pressure tester kit. The kit should include a fuel pressure gauge adapter that connects to the fuel filter outlet or the fuel rail. You can also attach a banjo fitting with a longer banjo bolt to the fuel filter outlet and connect it to a gauge.

When checking the fuel pressure, it is important to relieve the fuel line pressure before disconnecting any fuel lines to avoid leaks and the risk of an engine fire. You may also need to refer to the fuel filter instructions for details on relieving fuel line pressure.

Once you have connected the fuel pressure tester, start the engine and observe the gauge to see if the fuel pressure is within the normal range. If the pressure is low, there may be a problem with the fuel pump or a leak in the fuel system.

In addition to the fuel pressure, you can also test the fuel pressure sensor using a multimeter to probe the signal for 0psig. You can either run the fuel system and probe for a voltage output that matches your base fuel pressure or use a regulated air compressor to bench test the sensor.

It is important to note that working on fuel systems can be dangerous, and it is always recommended to seek professional assistance if you are unsure about any part of the process.

Fuel pressure problems

Common Fuel Pressure Issues

One of the most common fuel pressure problems in the Mitsubishi 3000GT is a faulty fuel pressure regulator (FPR). Symptoms of a malfunctioning FPR include erratic idling, sputtering when accelerating, and a lack of response from the RPMs. In some cases, the issue may lie with the fuel pump, which can cause similar symptoms.

Diagnosing Fuel Pressure Problems

To diagnose fuel pressure problems in the Mitsubishi 3000GT, it is recommended to perform a fuel pressure test. This can be done by attaching a fuel pressure gauge to the fuel rail or fuel filter outlet. However, it should be noted that the 3000GT does not have a test port, so an adapter may be required. By monitoring fuel pressure, owners can identify issues such as leaks or a failing fuel pump.

Solutions and Maintenance

In some cases, fuel pressure problems may be resolved by simply replacing the fuel filter or ensuring that the fuel hoses are properly connected and approved for submersible use. For more complex issues, such as a faulty FPR or fuel pump, replacement or repair may be necessary. It is also important to maintain proper fuel pressure to avoid engine damage and ensure optimal performance.

While the Mitsubishi 3000GT is a high-performance vehicle, it is not immune to fuel pressure problems. By understanding the common issues, diagnosis, and solutions, owners can effectively address these problems and maintain the performance and efficiency of their vehicles. Regular maintenance and monitoring of fuel pressure are crucial to keeping the 3000GT in top condition.

Frequently asked questions