All vehicles that use gasoline or diesel to run must have a way to get the fuel from the fuel tank to the engine. This is done with the use of an electric fuel pump. On modern or very old vehicles, a mechanical shaft would run a mechanical gear that would pump the fuel.
The fuel pump is located inside the fuel tank and is usually composed of an electric motor, a fuel level sensor, and, on some modern vehicles, an alcohol content sensor. This complete assembly is usually referred to as the fuel sending unit. On most newer cars, the individual components are not serviceable and the entire assembly has to be replaced.
How Much Does An In-Tank Fuel Pump Cost?
Since the fuel pump is located in the fuel tank, the labour can be quite high if the vehicle does not have an access panel. If this is the case, the fuel tank must be removed from the vehicle in order to service the fuel pump, which is much more labour-intensive.
Let us assume that independent shops’ labour rate is £70 an hour and that the dealership labour rate is £100 an hour. Below are some of the estimates for the fuel pump replacement cost:
- For a 2006 Honda Odyssey, the labour calls for 1.9 hours of labour and has an access panel, so removing the fuel tank is not needed for this vehicle. At an independent shop, the labour would cost £135, and an aftermarket fuel pump assembly would range between £80 and £135 depending on brand and price markup. At the dealership, the labour would cost £250 and a brand new Honda fuel pump assembly would range between $475 and $550 depending on location.
- For a 2009 Chevrolet Silverado, the labour calls for 2.6 hours of labour, and the fuel tank must be removed in order to replace the fuel pump. At an independent shop, the labour would cost £180 and an aftermarket fuel pump assembly would range between £65 and £135 depending on the brand used and the price markup. At the dealership, the labour would cost £345, and for a brand new Chevrolet fuel pump assembly, the price can range between £360 and £450 depending on location.
- For a 2012 Toyota Camry, the labour calls for 1.1 hours of labour. The fuel pump has an access panel, and the tank does not need to be removed on this vehicle. At an industrial shop, the labour would cost £75, and an aftermarket fuel pump assembly can range between £110 and £180 depending on brand and price markup. At the dealership, the labour would cost £145 and a brand new Toyota fuel pump assembly would cost between £405 and £495 depending on the region. On this vehicle, the pump can be replaced without replacing the entire unit. The cost of just the fuel pump without the sensors could range between £290 and £360.
Cost To Have a High-Pressure Fuel Pump Replaced
If your direct injection high-pressure fuel pump fails, your engine may still run at idle but might run roughly when attempting to drive. Because the engine needs the increased fuel pressure to run properly, replacing a failed high-pressure pump is mandatory even if your in-tank unit is still working properly.
Let us assume that the labour rate of independent shops is £70 an hour and £100 for the dealership. As always, labour rates may be different in each area.
- For a 2016 Ford Focus ST, the labour code calls for 1.4 hours of labour. At an independent shop, the labour would cost £100, and for an aftermarket high-pressure pump, it would range between £135 and £180. At the dealership, the labour cost would be £185 and for a brand new Ford high-pressure fuel pump, it would range between £225 and £270 depending on region.
- For a 2014 Honda Accord, the labour code calls for 2.1 hours of labour. At an independent shop, the labour cost would be £145, and for an aftermarket high-pressure pump, it would range between £250 and £340, depending on the brand. At the dealership, the labour would cost £275, and for a brand new Honda high-pressure pump, it would range between £495 and £585.
More About Fuel Pump
Some vehicles have a return line that sends unused fuel back to the fuel tank. On the other hand, most newer vehicles (2010 model year and up) use a returnless style fuel system.
The fuel sending unit is primed when the ignition is turned on, and once the engine is cranking, the sending unit provides fuel to the engine through the fuel rail. The fuel rail houses the fuel injectors, and the computer controls the amount of fuel to be injected into the engine.
On vehicles without direct injection, the fuel injectors spray fuel into the intake, which then allows the fuel and air to enter the combustion chamber at the same time through the intake valves. Direct injection engines tend to get carbon buildup on the intake valves as there is no fuel spraying onto the valves to clean them like non-direct injected engines.
For modern engines that use direct injection, a style of fuel injection where the fuel is injected directly into the combustion chamber, has two fuel pumps. These have the traditional in-tank sending unit as well as a high-pressure fuel pump that is usually located on the engine itself.
High-pressure fuel pump failure is much lower than the traditional in-tank units. The high-pressure pumps typically run off of the camshaft with a gear or piston to increase the fuel pressure to combat the extremely high pressure of the combustion chamber that the injectors are spraying fuel into.
When a fuel pump fails while driving, the engine will stall out as it has no fuel to burn. If the vehicle was off at the time the pump failed, the engine will turn over but will not start.
Some vehicles have two in-tank fuel pumps. Vehicles that have a gas tank that is split into two compartments will typically have one pump that transfers fuel from one side to the other (called the transfer pump). Then, the fuel-sending unit sends the fuel to the engine once it receives the fuel from the second compartment.
This setup is very common on German cars that are rear-wheel drive. Since the driveshaft runs down the middle of the vehicle, the fuel tank has one compartment on both sides of the drive shaft.
These fuel tanks are usually referred to as “saddle tanks” as that’s what they look like. Without a transfer pump, the main fuel pump has no way to get the fuel into the other compartment.
Fuel Tank Additives
Many aftermarket parts stores offer fuel tank additives that can be added to the fuel to help increase fuel economy or keep your injectors clean. Fuel has many additives from the fuel manufacturer, but sometimes additional additives can be beneficial.
Most of these are added directly to the fuel tank by the consumer. Always consult the directions as most additives recommend a full tank of fuel for proper use.
- Octane booster
Octane is a measurement for fuel. In simple terms, octane is a rating for your fuel of how much compression it can take before igniting with a spark. The higher the octane rating, the higher its ability to resist combusting before your engine is ready. The octane rating is the number you see at the gas station where the premium has the highest rating.
An octane booster is an additive you can add to your fuel to increase its octane rating. The Octane booster is only really intended for performance vehicles, as it is not needed for everyday cars as long as you are using the recommended fuel grade by the manufacturer.
Most octane boosters cost between £4 and £9, depending on the brand and size of the bottle.
- Fuel treatment additives
Fuel system cleaners or treatments are often found at parts stores, gas stations, or even places like Walmart. Some of the popular brands around are STP, Lucas, and Sta-Bil.
These fuel treatments have additional additives in them to help keep your fuel system clean. These chemicals help keep fuel lines, fuel pumps, and injectors flowing smoothly.
Some of these treatments have lubrication additives that help keep the fuel pump and injectors lubricated more than just the fuel alone. By decreasing friction, the components can last longer before failing.
- Fuel stabilizer additives
Another additive commonly found in parts stores and gas stations is fuel stabilisers. This additive is not intended for use in everyday driving vehicles but is geared for ones that tend to sit for long periods of time, like a weekend hotrod or for someone with a winter and summer vehicle.
When your vehicle sits for long periods of time, the gasoline will start to break down and deteriorate. Fuel stabilisers help protect the fuel from breaking down by adding special additives that help prevent deterioration.
Old fuel does not combust properly and can cause your vehicle to run poorly or even cause damage. For vehicles that sit for extended periods, adding a stabilising additive can help prevent this from happening.
How To Diagnose a Failing Fuel Pump
If you are experiencing performance issues while accelerating, you may have low fuel pressure due to a failing fuel pump. Technicians can troubleshoot this by performing a fuel pressure test. If the pressure is not within spec, your fuel pump should be replaced.
If your fuel gauge isn’t reading properly, the level indicator may not be working as intended. Technicians can troubleshoot this by making measurements on the level sensor. Most level sensors are built into the fuel pump assembly and require the entire fuel pump to be replaced.
If your vehicle cranks but does not start, you may have a failed fuel pump. Usually, when you turn the key to the “on” position, you can hear the electric pump prime for 2-3 seconds.
If you don’t hear that sound, your pump may have failed. This can be diagnosed by checking for fuel pressure and making sure the fuel pump is getting power when it’s supposed to.
What To Do If You Put The Wrong Fuel In Your Car
If you happen to put the wrong fuel into your vehicle, such as diesel or E85 into a standard gasoline vehicle, you will experience running problems. Depending on how empty the fuel tank was at the time, E85 could cause your vehicle to not run at all. If there was some regular gasoline in there, it could be diluted enough to run, but it would likely set a check engine light and run rough.
If you realise that the wrong fuel was pumped into the fuel tank, you must have the fuel tank drained and cleaned. If diesel was put into the tank and the vehicle was driven, the fuel injectors and fuel pump may become damaged.
Oftentimes, when a vehicle stalls out, the driver will attempt to start the engine by cranking. Cranking the engine can cause the spark plugs to become fouled out and may require replacement.
Wrong fuel in the car can be a costly repair to fix if any components are damaged in the process. If you notice that you have pumped the wrong fuel into your vehicle and have not yet driven it, it’s advised that you call a tow truck immediately and take it to a shop for the fuel to be removed. This will save you money by not having to run the fuel through the entire system.