12 13 ... Fault in fuel injection system

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

Fig 1: Identifying Ignition System Faults With Oscilloscope

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.