Fuel residue evaporates in the injector nozzles, leaving the waxy olefins behind. When the engine is shut off, the injectors undergo heat soak. The leaning out may cause higher than normal exhaust temperatures and turbo failure. If the injectors are dirty and can’t keep up with the engine’s demands, the fuel mixture will lean out, causing detonation to occur. When the engine is under boost and at a higher rpm, it needs all the fuel the injectors can deliver. In turbocharged engines, dirty injectors can have a dangerous leaning effect that may lead to engine-damaging detonation. On older multiport systems that fire the injectors simultaneously, the computer compensates by increasing the “on” time of all the injectors, which can create an overly rich fuel condition in the other cylinders.ĭirect fuel injectors are more sensitive to restrictions because of the precise amount of fuel they inject into the combustion chamber. When this occurs, unburned oxygen enters the exhaust and makes the O2 sensor read lean. If this precision is thrown off by restrictions, electrical problems or fuel problems, it can cause driveability issues. Here are 10 signs to look for when you need to replace a fuel injector or it needs service.Ī restriction of only 8% to 10% in a single fuel injector can lean out the fuel mixture and cause a misfire.
This has made them more precise in dispensing fuel.
During its evolution, the fuel injector has moved from the intake manifold to the combustion chamber.