System Operation

System Schematic:

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 pressure regulator
5. 2-way check valve
6. Charcoal canister
7. Canister purge VSV
8. ISC solenoid valve
9. A/T control module (A/T only)
10. Diagnosis switch terminal
11. Test switch terminal
12. ECM
13. "CHECK ENGINE" light
14. Ignition switch
15. Main fuse
16. Battery
17. Crank angle sensor (in distributor)
18. Ignition coil
19. Power unit (ignitor)
20. Vehicle speed sensor (in speedometer)
21. EGR VSV (CA. only)
22. EGR modulator (CA. only)
23. EGR valve (CA. only)
24. REGTS (CA. only)
25. Air valve
26. Intake manifold
27. PCV valve
28. Idle speed adjusting screw
29. Throttle body
30. Throttle position sensor (TPS)
31. Fuel injector
32. Water temperature sensor (WTS)
33. Exhaust manifold
34. Oxygen sensor
35. Air flow meter (AFM)
35.1. Air flow sensor
36. Air cleaner