Fuel Injector Replacement Cost

Once fuel arrives at the engine, most modern vehicles distribute the fuel to individual fuel injectors that regulate the amount of fuel used for each engine cycle.

Pressurized fuel is sent into the engine using fuel injectors. Each time an intake stroke occurs in the engine, the vehicle's computer will end a signal to fuel injectors, requesting they spray fuel. For heavy acceleration, the duration of the fuel spraying will be longer than if the engine were idling. Fuel injectors spray fuel into the cylinders in the same fashion as a household cleaner spray bottle, except that they are electronically actuated.

When a fuel injector fails or clogs, the engine suffers from fuel starvation, power is reduced, and misfires occur. These conditions may be intermittent, sudden, or increasingly worse. The check engine light will illuminate on the instrument cluster, and the fuel deliver system will be suspected based on the various on-board diagnostics trouble codes that are stored in the vehicle's memory. As the issue progresses, the engine may being to stall immediately after starting, fail to start, hesitate under throttle, or vibrate roughly.

It is not advisable to drive a vehicle with a fuel injector issue. A vehicle that stalls every few moments, and accelerates unpredictably is a hazard. The vehicle may also be impossible to drive, since the fuel cannot reach the engine. Also, lean operating conditions produce very high heat, and can damage internal engine and exhaust components.

On average, fuel injectors tend to fail after 80,000 miles, and require little maintenance during normal scheduled maintenance. To prolong the life of the fuel injectors, follow the scheduled maintenance intervals for cleaning the fuel delivery system and injectors.

If fuel delivery system symptoms are present, the technician will first conduct a visual inspection of the vehicle, and note any observed issues related to the fuel delivery system. If the fuel delivery system issue is not clear after a physical inspection, the servicing technician will connect a computerized scanner to the vehicle, and examine current conditions that are being reported by the various sensors in the vehicle. The stored OBD codes will provide information and direction for which components to inspect further. In the case of the fuel injector, the technician would most likely find that misfires are happening frequently on one engine cylinder. Once the technician suspects the fuel injector, the fuel injector(s) in question must be tested, and may require removal for further bench testing. When the round of testing is complete, any failed component must be replaced, and the vehicle will be tested to ensure the customer complaint does not return.

Most modern vehicles require the intake manifold to be removed to replace the fuel injectors. This can be a large job that may involve draining the engine coolant and engine oil, removing many engine components, and replacement of the intake manifold gasket. Many vehicles, however, are designed with plastic intake manifolds that do not have oil passages or coolant passages, and are much faster and more cost effective to remove and reinstall. Once access is available, the fuel injector is disconnected from the fuel rail and electrical connector, and removed. Replacement is the reverse.

When replacing fuel injectors, using the OEM fuel injectors is the best choice for most applications, and this is especially true when replacing only one or two fuel injectors. Keeping the injectors the same will ensure even power across the engine, and proper air/fuel mixture for all cylinders. This should result in a smooth running engine.

Fuel plays a large role in the health of an engine, and fuel system. It is best to ensure you are adding fuel of the appropriate grade for your engine, according to the instructions in the owner's manual. When working with fuel, the battery should always be disconnected, and proper precautions taken against fire hazards.

Fuel injector replacement should be left to a professional in most cases. The risk of fire due to electrical components and fuel in close proximity is enough by itself, but this repair can turn very complicated. A good amount of knowledge goes into removing the injectors, intake manifold, fuel rail, and other components, and attempting without knowledge of these components could lead to injury or vehicle damage.