Fuel Pump And Coil: When To Replace Both?

Fuel pump replacement is a complex task that involves dropping the fuel tank, removing and replacing the fuel pump assembly, and testing the work. However, there is no definitive answer to whether the coil should be replaced at the same time. Some automotive experts recommend replacing the fuel pump as a preventative measure at high mileage, while others suggest addressing fuel pressure issues first to detect any problems in the fuel delivery system. In any case, it is essential to consult a qualified mechanic or refer to a reliable vehicle repair manual for guidance on fuel pump and coil replacement.

Fuel pump replacement is not a simple task

Firstly, fuel pump replacement can vary depending on the vehicle's specific design. While the basic steps remain similar, the location of the fuel pump and the level of accessibility can differ significantly. In some cases, the fuel pump may be easily accessible through an access panel, while in other cases, it may be necessary to remove the fuel tank or even the back seat to reach the pump. This variation in accessibility can greatly impact the complexity and time required for the replacement.

Secondly, safety is a critical concern during fuel pump replacement. As fuel is highly flammable, it is essential to work in a well-ventilated area away from any potential sources of ignition, such as open flames or sparks. Wearing proper safety gear, including safety glasses and gloves, is crucial to protect yourself from injury. Additionally, relieving fuel pressure before opening the fuel system is essential to prevent the risk of fire and injury due to releasing fuel under pressure.

Thirdly, the replacement process itself involves multiple steps and requires a certain level of mechanical skill and knowledge. It typically includes locating and verifying the fuel pump, checking fuses and relays, relieving fuel system pressure, draining the fuel tank, disconnecting and reconnecting various components, and conducting a road test to ensure a successful repair. Each of these steps must be carefully executed to avoid complications and ensure the fuel pump functions correctly.

Furthermore, fuel pump replacement can be physically demanding. It often requires lifting the vehicle, removing and lowering the fuel tank, and working in tight or uncomfortable spaces. This process can be time-consuming and strenuous, especially for those without the necessary tools, equipment, or physical capability.

Lastly, fuel pump replacement can be costly. The pump itself may cost anywhere from $75 to $200, while labor costs can vary significantly depending on the vehicle's accessibility. If the fuel tank needs to be removed, the labor costs can easily exceed $300, and for diesel or direct-injection pumps, the total replacement cost could surpass a thousand dollars.

In conclusion, fuel pump replacement is not a simple task. It requires careful planning, attention to safety, mechanical skill, physical effort, and financial investment. While it may be tempting to attempt a fuel pump replacement independently, it is generally advisable to seek professional assistance or, at the very least, have a thorough understanding of the process and the potential challenges involved.

A fuel pump replacement should be accompanied by a fuel filter replacement

New fuel pump modules usually come with a new filter or sock as part of the assembly, but if a customer is replacing the pump separately, they should also change the filter and pickup screen. On vehicles that have inline fuel filters, there may be a recommended service interval of typically 50,000 miles. However, if the filter becomes clogged with dirt, rust or sediment from the fuel tank, it may have to be replaced sooner.

Frequent fuel filter clogging could be a sign that the fuel tank is being contaminated with outside dirt, or that it is rusting (in the case of a steel tank) or flaking (in the case of an older plastic tank). In this case, the fix may require cleaning or replacing the fuel tank. A common symptom of a clogged fuel filter is a loss of high-speed power caused by a restriction in fuel flow when engine demand is high. If the filter becomes completely blocked, it will starve the engine of fuel, causing the engine to die.

Therefore, it is advisable to replace the fuel filter when replacing the fuel pump, especially if the fuel filter is old and has not been replaced in a while. This will help ensure that the fuel system is clean and functioning properly, and prevent potential issues down the line.

A non-running fuel pump may have a wiring issue

If you are having issues with the fuel system and are still running the original pump, it is recommended to check the pump hat's connector for the wiring harness from the car. There is a known problem with its design and operation, and it will eventually fail. If you replace your fuel pump, the new OEM pump should come with a kit to change the wiring. This is also a good opportunity to extend the harness to add a little strain relief.

If you are experiencing issues with your fuel pump, a mechanic can check the wiring and determine if there is a problem. They may also check the fuel pressure with a gauge under the hood to diagnose the issue.

To achieve maximum output and safety with a custom-wired electric fuel pump, a properly designed electrical wiring scheme is required. Max output means minimal voltage drop between the electric current supplier (the battery and alternator) and the consumer (the fuel pump). Max safety means a failsafe in the circuit design that prevents the fuel pump from continuing to run after a crash or engine failure.

In summary, if your fuel pump is not running, it is important to consult a mechanic to diagnose the issue. They will be able to check the wiring and fuel pressure to determine the cause of the problem and recommend the necessary repairs or replacements.

A fuel pump is generally located inside the fuel tank

In some vehicles, the fuel pump can be accessed through a fuel pump access door underneath the rear seat. However, in other vehicles, the fuel tank must be dropped or removed to access the pump. This often involves emptying the tank and sometimes removing parts of the exhaust system.

In carbureted engines, a low-pressure mechanical pump is typically mounted on the engine. These pumps operate at a relatively low fuel pressure of 10-15 psi.

Modern vehicles with gasoline direct injection (GDI) have a second, high-pressure pump located near the fuel rail in the engine compartment. This type of pump is used for high-pressure direct injection systems.

A fuel pump replacement should also include a check of the pump’s connectors

When replacing a fuel pump, it is important to consider other components of the vehicle that may need attention. The fuel pump is responsible for moving gasoline from the tank to the engine compartment, where it is sprayed into the engine through the fuel injectors. It is typically mounted inside the fuel tank and can be difficult to access, often requiring the removal of the fuel tank itself.

Given the complexity of this process, it is recommended that a fuel pump replacement includes a thorough check of the pump's connectors. This involves inspecting the connectors on both sides of the plugs to ensure they are not burnt or overworked. By doing so, potential issues with fuel delivery can be identified and addressed, preventing future problems and ensuring the safety of the vehicle.

In addition to checking the pump's connectors, it is also advisable to replace the fuel filter during a fuel pump replacement. This is because the fuel filter plays a crucial role in keeping the fuel system free from debris and contaminants, which can cause damage to the engine.

Furthermore, it is worth noting that fuel pump issues can often be challenging to diagnose. While common symptoms such as a lack of power, engine starting problems, and unusual noises may indicate a faulty fuel pump, these issues can also be caused by problems with other systems. Therefore, it is recommended to consult a mechanic or refer to a vehicle repair manual for accurate diagnosis and repair.

Additionally, preventative maintenance of the fuel pump can be considered. While not always necessary, replacing the fuel pump before it breaks can provide peace of mind and avoid potential inconveniences, such as being stranded with a non-functioning vehicle. However, the decision to replace a fuel pump preventatively should be made carefully, taking into account factors such as the age of the vehicle, its mileage, and the potential costs involved.

Frequently asked questions