Fuel Injection System - HONDA PGM-FI: Testing: Injector

NOTE: Check idle speed, ignition timing, valve clearance and idle CO % before condemning injector(s).

With engine idling, disconnect injector couplers and note change in idle speed. If idle speed drop is consistent for all injectors, injectors are normal.
Also, check for a clicking sound of each injector using a stethoscope during engine idle. If any injector fails to emit typical clicking sound, check wiring between ECU and injector. If necessary, replace injector.