System Operation

System Diagram:

The Electronic Fuel Injection system in this vehicle supplies the combustion chambers with air/fuel mixture of optimized ratio under widely varying driving conditions.

It uses the multi-point fuel injection system which injects fuel into each intake port of the cylinder head.


This system has 3 major sub-systems: air intake system, fuel delivery system and electronic control system. Air delivery system includes air cleaner, air flow meter, throttle body, air valve, idle speed control (ISC) solenoid valve and intake manifold. Fuel delivery system includes fuel pump, delivery pipe, pressure regulator, etc..

Electronic control system includes ECM, various sensors and controlled devices.


This section explains not only the system related to the electronic fuel injection but also such functions of ECM as listed below.


- EGR control system.

- Idle speed control valve system.

- ESA (Electronic Spark Advance) system.

- Fuel pump control system

- Fuel injection control system

- Evaporative emission control system

NUMBERED COMPONENTS IN ILLUSTRATION
1. Fuel tank
2. Fuel pump
3. Fuel filter
4. Fuel pump relay
5. Fuel injector resistor
6. Fuel injector
7. Fuel pressure regulator
8. Throttle body
9. Pressure sensor
10. WTS
11 TPS
12. Air valve
13. PCV Valve
14. Power steering VSV (if equipped)
15. Intake manifold
16. Exhaust manifold
17. O2 sensor
18. Three-Way catalyst
19. ATS
20. ISC solenoid valve
21. A/C VSV (if equipped)
22. A/C amplifier (if equipped)
23. CAS (in distributor)
25. Idle speed adjusting screw
26. EGR valve
27. EGR modulator
28. EGR VSV
29. BVSV
30. Charcoal canister
31. Diagnosis switch terminal
32. Test switch terminal
33. ECM
34 Electric load signal
- Radiator fan
- Heater blower
- Rear window defogger
- Stop light
- Lighting system
35. A/T control unit
36. Vehicle speed sensor
37. Ignitor
38. Ignition coil
39. "CHECK ENGINE" light
40. "Shift-Up" indicator light
41. Main relay
42. Main switch
43. Clutch switch (M/T) - Shift position switch (A/T)
44. Starter magnetic switch
45. Main fuse
46. Battery
47. Power steering switch