BMW Cars 1999-06

Basic Fuel System Diagnosis


When there is a problem starting or driving a vehicle, two of the most important checks involve the ignition and the fuel systems. The questions most mechanics attempt to answer first, "is there spark-" and "is there fuel-" will often lead to solving most basic problems. Please refer to the information on engine electrical components and ignition systems for ignition system diagnosis and testing. If the ignition system checks out (there is spark), then you must determine if the fuel system is operating properly (is there fuel-).