Hyundai Sonata LF: Engine Control System / Injector Troubleshooting
The three waveforms below are taken from the #1 and #4
injectors. The top waveform is from the high side (feed side) of the #1
and #4 injectors, while the middle waveform is from the low side (ground
side) of the #1 injector and the bottom waveform is from the low side
of the #4 injector.
The middle waveform is the same as the top waveform because
there is no ground for the circuit. With no current flowing in the
circuit, the #1 injector is not energized and fuel does not flow.
The bottom waveform shows that ground is supplied and there
is a voltage drop across the #4 injector. With current flowing in the
circuit, the #4 injector is energized and fuel flows.

Other information:
Components
1. Screw2. Front housing3. Stop ring4. Stopper5. Overrunning clutch6. Lever7. Lever plate8. Lever packing9. Magnet switch assembly10. Armature assembly11. Yoke assembly12. Brush (-)13. Brush holder14. Brush (+)15. Rear bracket16. Through bolt17...
C..