Common causes of fuel injector faliure

A properly maintained fuel system is the key to reducing deposits that plug up fuel injectors.  When fuel injectors are contaminated the efficiency and performance of your engine can suffer greatly. 

There are two major ways an injector can fail.  The most common is from contamination in your fuel system. When your injectors are contaminated you will notice loss of engine power,pooer throttle response, lack of fuel economy, hard starting issues (due to leaking injectors)and hesitation during acceleration.

Another way fuel injectors can fail is by electronically shorting out. Every fuel injector has a copper winding inside, which is referred to as the "coil". This coil is coated in a type of varnish to protect the copper from being decomposed by gasoline.  Overtime this protective coating will break down from the cleaning agents added to gasoline. The end result is a shorted coil.

Here are some signs of a shorted coil.


1) A bad ohm reading. The coil resistance can be measured with a multi-meter at the fuel injectors plug terminals. Most fuel injectors should measure between 12.5 and 16.5 ohms.  However, there are some injectors reffered to as "peak and hold" that should have a reading of 2.0-3.5 ohms these injectors are common on turbo charged applications.  All Throttle body injectors "TBI" should have a reading of 1.8-2.5 ohms. Your vehicles owners manual should give you the peramiters of the injector resistance.
2) A shorted fuel injector coil will begin with symptoms of poor idle, lack of power and end with drivability issues. These symptoms are caused by the coil not responding to the electricity being applied to the injector.  Basically what is happening is that the injector is becomming "lazy" not spraying fuel at the right time or completly closing at the right time.
When the coil fails the fuel injector must be replaced with a new or reconditioned unit.