Page 580 of 1574

1F1-48 M162 ENGINE CONTROLSA . Valves Closed
B. Valves Opened
The pressure difference between the fuel pressure and the intake manifold is about 3.8 bars during the full load. The spring chamber(9) is connected to the intake manifold with the vacuum hose at the intake pipe connection(7). Thenegative pressure generated in the intake manifold activates the diaphragm, and thus the fuel pressure gets reduced to the rate of the operating extent of the diaphragm by the intakemanifold's negative pressure.
Consequently, the fuel pressure in the fuel distributor changes by the intake manifold's negative pressure, and the injector'sfuel pressure gets reduced independently to the throttle valve'sposition. Thus, the fuel injection volume can only be determined according to the injector's injecting duration. 2. Fuel return line
3. Valve
5. Diaphragm
6. Compression Spring
8. Fuel Chamber
9. Spring Chamber
1. Fuel Pressure Regulator
2. Intake Manifold
3. Fuel Return(to fuel tank)
4. Fuel Supply(form fuel pump)
5. Fuel Pressure(approx. 3.8 bars)
6. Intake Manifold Negative Pressure(0 bar)
Function of the Fuel Pressure Regulator The fuel pressure regulator maintains the fuel pressure in the fuel line with the pressure of 3.2 bars to 3.8 bars according tothe intake manifold pressure. This operating pressure cannotbe changed, and the fuel injection volume will be only determined by the injection time. Over supplied fuel returns to the fuel tank through the return line. There is no negative pressure applied to the spring chamber(9) during the full load, and it is separated from the fuel chamber(8)by the diaphragm(5). When the fuel pressure goes up, the diaphragm forces the compression spring(6) in the direction of compression . At thismoment, the valve(3) sticks to the diaphragm by the fuelpressure, and the fuel return line(2) opens. The fuel over supplied returns to the fuel tank through the return line.
Page 820 of 1574
POWER BOOSTER 4C-5
PEDAL STROKE INSPECTION
1. Start the engine and stop it after one or two minutes.Depress the brake pedal several times. If the pedal goes down furthest the first time, but gradually rises after the second or third time, brake booster is normal.If there is no change in pedal stroke, the brake booster is abnormal.
2. Depress the brake pedal several times with engine stopped, and depress the brake pedal and start the engine. If the
pedal goes down slightly, the booster is normal.
3. Depress the brake pedal with engine running, and stop it with the pedal depressed. If there is no change in pedalheight during 30 sec., the booster is normal.
Page 824 of 1574
4D-4 FRONT DISC BRAKES
5. Pull out the brake pads. Replace pads if necessary.Notice Always change the all pads on one wheel at a time.
6. Installation should follow the removal procedure in the reverse order.
7. Bleed the air from the system.
Page 825 of 1574