Switching Up Your Car's Fuel Source: Is It Possible?

Changing the fuel source of your car is a complex process that requires careful consideration and compliance with legal and safety regulations. While it is possible to convert a car to run on natural gas, which is cheaper and more abundant, there are technological and legal challenges to navigate. The conversion process can cost thousands of dollars upfront and may involve hiring a certified installer to comply with the Clean Air Act. Additionally, there are safety concerns when dealing with fuel systems, and it is crucial to have the necessary knowledge and equipment to avoid accidents.

How to change a fuel pump

Changing a fuel pump can be a challenging task, but it can be done safely if you take your time and follow the instructions for your particular vehicle. Here is a step-by-step guide on how to change a fuel pump:

Prepare Your Vehicle:

Firstly, park your vehicle on a firm, level surface and engage the parking brake. It is important to work in a well-ventilated area, preferably outdoors, to minimise the risk of inhaling harmful fumes and to reduce the chance of fire. Ensure you are wearing proper safety gear, including safety glasses, gloves, and appropriate clothing.

Locate the Fuel Pump:

Most vehicles' fuel pumps are located inside the fuel tank. Open the fuel cap and turn the key to the 'ON' position. If your fuel pump is functioning correctly, you should hear a faint hum for two to three seconds. If there is no sound, it may be necessary to replace the pump.

Check the Fuse and Relay:

Find and verify the fuel pump fuse and relay. If the fuse is blown, replace it with one of the same amperage and check if the fuel pump is now operational. If the fuse and relay are functional, check for power and ground at the fuel pump. If there is power and ground, then the pump is faulty and needs to be replaced.

Relieve the Fuel System Pressure:

To do this, disconnect the negative battery cable. If your vehicle has a fuel injection system, you will need to depressurise the fuel system. Open the fuel filler cap and loosen it until you hear the sound of escaping pressure. Then, locate and remove the fuel pump fuse or relay. Start the engine, and pull out the fuse or relay—if it is the correct one, the engine should stall.

Drain the Fuel Tank:

If possible, drain or siphon as much fuel as possible from the tank to reduce the risk of spills and make the tank lighter and easier to handle.

Remove the Fuel Tank:

In many cases, it may be necessary to remove the fuel tank from the vehicle. This process varies depending on the vehicle, and you may need to use a jack to support and lower the tank. Alternatively, some vehicles may have an access port under the rear seat or in the trunk area, which can be used instead of removing the tank.

Disconnect the Fuel Lines and Electrical Connections:

Before removing the old fuel pump, make sure to note the fuel line connections and wiring. Disconnect the filler tube hose and the electrical connection to the pump. Support the fuel tank with a jack and a block of wood, and remove any retaining straps or bolts holding the tank in place.

Remove the Old Fuel Pump:

Once the connections have been disconnected and the tank is accessible, remove the old fuel pump. Loosen or remove the fuel pump retainer ring and carefully take out the pump, along with the sender module.

Install the New Fuel Pump:

Compare the new fuel pump with the old one to ensure they are identical. Clean the mounting area and seal the surface using a shop towel and carburettor cleaner. Install a new O-ring gasket/seal if necessary. Secure the new fuel pump in place using the mounting bolts, ensuring everything is tightly secured.

Reassemble the Fuel System:

Reconnect the fuel lines and electrical connectors. Reinstall the fuel tank by securing the retaining straps and reconnecting any other necessary components. Fill the tank with fuel and conduct a road test to confirm that the new fuel pump is functioning correctly.

Tips:

• It is important to consult your vehicle's service manual or online tutorials for specific guidance on replacing the fuel pump in your particular make and model.
• Always work in a well-ventilated area to minimise the risk of fire and inhalation of fumes.
• Wear proper safety gear, including safety glasses and gloves, to protect yourself from fuel spills and splashes.
• If possible, drain the fuel tank to reduce the risk of spills and make it easier to handle.
• Before removing the old fuel pump, clean the area to prevent dirt and debris from falling into the fuel tank.
• Consider replacing related components, such as the fuel filter, fuel pump strainer, and fuel tank O-ring or gasket.

When to Replace a Fuel Pump:

Some common symptoms of a faulty fuel pump include:

• Difficulty starting the car
• Sudden loss of power while driving
• Engine stalling or rough running
• Strange, high-pitched whining noises coming from the fuel tank area
• Increased frequency of refuelling
• Engine sputtering, especially at high speeds
• Overheating

Signs of a bad fuel filter

It is important to keep an eye out for bad fuel filter symptoms as they can cause serious issues with your car engine. Fuel filters are designed to keep dirt, rust, paint chips, and other fuel contaminants from entering fuel injectors and harming the engine. Experts recommend replacing the fuel filter in your vehicle every two years or 20,000 to 30,000 miles. Here are some signs that indicate you need to replace your fuel filter:

• Power Loss When Under Load: A blocked fuel filter can restrict fuel flow to the engine, resulting in reduced power output when the vehicle is under load.
• Check Engine Light is On: If the fuel injectors don't receive enough pressurized fuel, there may not be enough fuel sprayed into the cylinders. This can trigger the Check Engine Light.
• Engine Runs Rough or Stalls: Insufficient fuel supply to the engine can cause it to stumble or stall while driving or idling.
• Engine Won't Start: A clogged fuel filter may prevent the fuel from pressurizing properly, resulting in the engine not starting or starting briefly and then dying.
• Decreased Fuel Economy: The vehicle's computer may compensate for a perceived lean air-fuel mixture by commanding more fuel to be injected, resulting in higher fuel consumption.
• Loud Noises from the Fuel Pump: Unusual noises coming from the fuel pump could indicate that it is struggling to send fuel through a dirty fuel filter.
• Engine Sputtering: A clogged fuel filter can cause the engine to sputter, especially when turning the ignition or maintaining high speeds.
• Poor Engine Performance: A dirty fuel filter can interfere with fuel delivery to the engine, resulting in reduced speed, handling, and performance, especially at high speeds or when carrying heavy loads.
• Damaged Fuel Pump: A dirty fuel filter can put stress on the fuel pump, leading to potential damage or failure.

Compressed-natural-gas (CNG) conversion

Compressed-natural-gas (CNG) is a fuel gas that is mainly composed of methane. It is stored and distributed in hard containers, usually in cylindrical or spherical shapes. CNG is used in traditional petrol or internal combustion engine vehicles that have been modified or in vehicles specifically manufactured for CNG use. Any existing petrol vehicle can be converted to a dual-fuel petrol/CNG vehicle.

The cost of installing a CNG conversion kit can often reach $8,000 for passenger cars and light trucks, and is usually reserved for vehicles that travel many miles each year. CNG costs about 50% less than petrol and emits up to 90% fewer emissions. A properly installed conversion will run anywhere from $6,500 for a basic system to $12,000 for a top-of-the-line installation with a high-capacity, composite fuel tank.

There are four types of CNG tanks, each lighter and more expensive than the next. Type I is an all-metal tank, generally made of steel or aluminium. Type II is a thinner metal tank wrapped in the middle with a fibreglass or carbon composite. Type III is a thinner metal tank fully wrapped in composite. Type IV is a plastic tank fully wrapped in carbon-fibre composite—very lightweight, but it comes at a hefty price.

To convert a petrol-burning engine to one that runs on CNG, you will need to attach a regulator, which reduces tank pressure from 3600 psi to 125 psi, to the fuel tank. Fuel is then fed to a parallel fuel rail and to new secondary injectors plugged into an adapter. A wiring harness plugs into the factory engine-control unit and intercepts throttle information, sending it to a new fuelling computer, which slightly alters the data and passes it to the CNG injectors through a parallel wiring harness.

Replacing a fuel tank

Drain the Old Fuel Tank:

First, you need to drain the fuel from the old tank. Many tanks have a small stop valve or a drain cock that allows you to neatly drain the fuel. Simply loosen the valve and let the fuel run into a proper fuel storage container. If your tank doesn't have a valve, you'll need to remove one of the fuel lines to drain the tank.

Remove the Fuel Lines:

There are usually two fuel lines going into the tank: a smaller line at the bottom that directs fuel to the engine, and a larger line at the top used for filling the tank. There may also be a third line, an air-line, that allows for pressure release. Detach all these lines from the old tank.

Drop the Rear Suspension (if necessary):

In some cases, you may need to drop the rear suspension to access the old tank. This involves supporting the rear suspension with a jack, disconnecting the bottom fittings on the rear shock absorbers, and then slowly lowering the heavy parts. You may also need to disconnect the rear brake lines to avoid damaging them.

Remove the Old Fuel Tank:

The fuel tank is typically held in place by two metal straps that are bolted in place. Loosen the nuts at one end of the straps and remove them. With the straps removed, you can now drop the old fuel tank.

Install the New Fuel Tank:

Putting in the new fuel tank is simply a matter of reversing the removal process. Place the new tank in position and secure it with the metal straps. Reattach the fuel lines, ensuring they are snugly fitted to prevent leakage.

Final Checks:

Once the new tank is installed, fill it with fuel and inspect for any drips or leaks. Check that the tank is secure and all lines are properly connected. Start the engine and let it run for a few minutes, ensuring there are no fuel leaks.

Remember to work in a well-ventilated area when dealing with fuel, and always have a fire extinguisher (preferably a Class B extinguisher) nearby as fuel is highly flammable. It's also a good idea to take pictures and notes during the process, so you know how to put everything back together correctly.

Replacing a fuel filter

The fuel filter is a simple device that strains the fuel before it passes to your engine. It is important to change the fuel filter regularly, as recommended by the manufacturer, to prevent contaminants from entering the fuel system and causing damage. Here is a step-by-step guide on how to replace a fuel filter:

Step 1: Relieve Fuel Pressure

• Locate the fuse or relay for the fuel pump and unplug it.
• Attempt to start the vehicle. If the correct circuit has been disconnected, the engine will turn over but not start, or it may run for a few seconds before dying.
• Shut off the engine and let it cool if it was running.

Step 2: Find the Fuel Filter

• Check the vehicle's repair manual to locate the fuel filter. It is usually located along the fuel line between the fuel tank and the engine.
• If you need to access the underside of the vehicle, use a jack to raise it and place it on jack stands.
• Note the position of the fuel filter, as the new one will need to be installed in the same direction.

Step 3: Disconnect and Remove the Old Filter

• Place a drain pan or container under the fuel filter to catch any spilled fuel.
• Disconnect the fuel lines from both ends of the fuel filter. Be prepared for some fuel to spill out.
• Remove any retaining clips or bolts holding the fuel filter in place.
• Carefully remove the old fuel filter.

Step 4: Install the New Filter

• Ensure the new fuel filter is the correct type and size for your vehicle.
• Install the new fuel filter in the correct direction, following the arrow on the filter body indicating the direction of fuel flow.
• Secure the new fuel filter in place using bolts or clips.
• Reconnect the fuel lines to the new filter and replace any retaining clips.

Step 5: Reinstall the Fuse or Relay and Check for Leaks

• Reinstall the fuel pump fuse or relay.
• Start the vehicle and check for any fuel leaks around the new fuel filter.
• If there are no leaks, the job is complete. If leaks are present, tighten connections as needed.

Frequently asked questions