Fault In Fuel Injection System

Evaluation of ignition voltage peaks in response to sudden accelerator loads. See Fig 1.

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