12 13... Fault in fuel injection system

Evaluation of ignition voltage peaks in response to sudden accelerator loads.

Fig 1: Identifying Ignition System Faults

Courtesy of BMW OF NORTH AMERICA, INC.

1. Beginning of dying-out process is not much higher than ignition voltage peak. Ignition system is OK.
2. Beginning of dying-out process is considerably higher than ignition voltage peak. Fault in injection system:
   • lean mixture
   • defective injection valve
   • low compressions