Fuel injection lines are the rubber hoses that vehicles with fuel injection systems are equipped with. They are very similar in appearance and function to regular fuel hoses, however they are strengthened with additional layers that allow them to hold the significantly higher pressures generated by fuel injection systems. Fuel injection systems routinely produce pressures upwards of 50 psi, which is higher than what regular fuel hoses are designed to hold. While it is not typically a common issue, fuel lines are susceptible to issues, especially in high mileage vehicles. Aside from leaks, bad fuel injection lines can cause performance issues with the vehicle and even render the vehicle undrivable. Usually a bad or failing fuel hose will produce a few symptoms that can alert the driver of a potential problem.
1. Fuel odor
One of the first symptoms of possible issue with fuel injection lines is a fuel odor coming from the vehicle. Over time fuel hoses can dry out, and begin to leak fuel vapors. Small leaks that emit fuel vapors will produce a faint, or sometimes strong odor of gasoline due to the leak. Usually small leaks such as these will progress into larger leaks that can cause more serious issues.
2. Engine misfires, hard starting, and stalling
Another symptom of an issue with fuel injection lines is engine performance issues. If any of the vehicle’s fuel lines develop any sort of leak the performance of the fuel system, and in turn the engine, can be compromised. A fuel leak due to a worn or damaged hose can cause the vehicle to experience issues such as misfires, hard starting, stalling, and can even prevent the vehicle from running at all.
3. Fuel leaks
Another, more serious symptom of an issue with the vehicle’s fuel injection lines is visible fuel leaks. If any of the lines wear out and rupture it will cause the vehicle to leak fuel. Leaky fuel lines will produce drips, or in more serious cases, puddles of fuel on the undersides of the vehicle. Depending on which fuel injection lines are leaking, the fuel leaks will usually be at the front or rear of the vehicle. Usually fuel leaks that are large enough to produce visible puddles will also cause performance issues, and should be attended to as quickly as possible to prevent them from becoming a safety hazard.
While most fuel injection lines will last well into high mileage service, they can eventually wear out, or break down and cause issues. As any sort of fuel injection line issues can lead to fuel leaks, any problems found should be taken care of as soon as possible to prevent them from progressing into more serious issues, and even a potential safety hazard. If you suspect that your vehicle may be having an issue with one or more of the fuel injection lines have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the lines should be replaced.
This article originally appeared on YourMechanic.com as Symptoms of Bad or Failing Fuel Injection Lines and was authored by Eduardo Ruelas.