The combustion system of your vehicle depends on your Pontiac fuel injectors to measure the amount and timing of fuel to your engine's cylinder. Each injector depends on a valve, which is electronically controlled, to let fuel into the engine. Each injector has a set of small holes at to spray fuel into the engine, but only at well-controlled amounts. The timing - how long the injection nozzle's remains open-- will determine how much fuel is injected. The timing and pressure of the fuel injection is controlled by sensors and an on-board computer. The latest technology in combustion technology scene has been the direct injection systems. These systems feature an injection nozzle that is placed inside the combustion chamber itself. The piston uses a depression where initial combustion takes place. Direct injection systems are seen in a lot of diesel and European models. In the U.S., you will see more multi-port fuel injection or sequential port fuel injection systems. With multi-ports, there is a fuel injector for each cylinder in the engine, and each fuel injector is located close enough to spray directly into the intake valve. Sequential multi-port fuel injection systems use one injector that opens precisely before the intake valve of the cylinder opens. When you start to notice the symptoms of fuel injector failure, including misfires, detonations and lean misfires, then order a new set of Pontiac fuel injectors from our site, and enjoy a smooth ride again.