Understand your
Fuel Injected
Engine:

Symptoms of Injector Problems

Lack of Power
Vehicle has lost it's performance

Poor Fuel Economy
Vehicle uses excessive amount of fuel

Excessive Exhaust Emissions
Vehicle fails emissions test & O2 sensor failure

Hard Starting
The vehicle is difficult to start, hot or cold

Rough Idle
The vehicle does not idle smoothly

Poor Driveability
The vehicle suffers with hesitation and pings
Gasoline Injectors: what everyone needs to know.

Increasing demands are being made globally on vehicle manufacturers to:

· reduce exhaust pollution,
· improve fuel economy,
· increase engine performance and
· reduce service and repair costs.

Consequently, the modern electronic fuel injection system is being fitted as standard on new gasoline engine vehicles produced worldwide.

Crucial to this system is the fuel injector valve, an electronically controlled mechanical valve manufactured to tolerances as small as 1 micron. This valve operates on opening times of between 2 and 15 milliseconds. The fuel inlet port is protected by a fine 20 micron filter screen and, when the valve is opened by an electronic pulse, a precise amount of pressurized fuel is forced through small metering hole or holes.

The whole injection system depends upon the reliability, accuracy and performance of fuel injectors working to extremely fine tolerances.

The inside dirt: What happens to injectors?

Problems start to occur when deposits, created by chemical contaminates in gasoline as well as the petrol itself, build up on surfaces of the injector - such as the filter screen, pintle valve, pintle head and valve seat. Heat soak also dries gasoline leaving residue. These contaminates bake onto injector parts. Such build ups can dramatically change the performance of the injector and therefore the car's engine.

 Tests have shown that a build up inside the injector of only 5 micron can reduce the flow rate through the injector by up to 25%. Any contamination on or in the injector can affect the fuel flow rate as well as changing the fuel droplet size, reducing the combustible content of fuel, causing excessive exhaust pollution, poor fuel consumption and impaired engine performance.

Diagnosing injector performance.

Today's vehicles are fitted with self-diagnostic electronics that quickly and accurately pin point a faulty electronic engine component, even while the car is being driven.

The injectors however are part electrical and part mechanical and as we have seen, it is the mechanical aspect of the injector that is crucial to the engine's efficiency and easily affected by contamination.

The mechanical performance of injectors cannot be accurately analyzed, checked or tested while they are still in the car. Injectors must be removed from the engine and carefully analyzed for leaks, spray pattern atomizations and actual fuel delivery volumes in a comprehensive diagnostic simulation program. All too often injectors are overlooked during the common engine diagnostic tests.