Technical characteristics of the fuel injection system «Multec SPI» (Opel Kadett E)

The C16NZ engine is equipped with a single-point system (undistributed) fuel injection "Multec SPI" general Motors company.

Signals from the system sensors are sent to the controller (microprocessor control unit), which determines the duration of the injection nozzle opening and controls the operation of the idle speed controller, and also carries out software control of the ignition advance angle. The controller has a self-diagnostic system.

Data for verification and adjustment

Engine crankshaft speed at idle, rpm: 720-880.

Carbon monoxide (CO) content in exhaust gases, %: <0,4.

Fuel pump

The electric roller submersible fuel pump is installed in the fuel tank and controlled by the controller.

Supply voltage, V: 7-15.

Productivity at terminal voltage of 12 V, l/h: 85.

Controller

The controller is installed on the right front pillar of the body under the instrument panel. It controls the operation of the fuel pump relay, injection nozzle, idle speed controller and performs self-diagnostics.

Injection nozzle

The electromagnetic injection nozzle is installed in the housing above the throttle valve.

Winding resistance, Ohm:

• on a cold engine: approximately 1.4-1.8;
• on a hot engine 5 minutes after it has been stopped: approximately 0.2 Ohm more than the resistance value on a cold engine.

Fuel pressure regulator

The fuel pressure regulator is installed on the throttle body and serves to maintain the pressure at a given level.

Fuel inlet pressure, kg/cm²: 0.7-0.8.

Throttle position sensor

The potentiometric throttle position sensor is mounted on the throttle shaft. The signal from the sensor is used to determine the engine operating mode (idle, partial load or full power).

Potentiometer resistance when measured between terminals, kOhm:

• "A" and "B" (constant resistance): 4-9;
• "B" and "C" (with the throttle valve closed): 1-3;
• "B" and "C" (with the throttle fully open): 5-10.

Voltage when measured between terminals "A" and "B", V: 4.7-5.1.

Idle speed control valve

The idle speed controller is made in the form of a stepper motor. which actuates a valve that changes the flow section of the air channel, made parallel to the throttle valve. According to the controller commands, the controller maintains the engine idle speed within specified limits, regardless of the load.

Resistance of electric motor windings when measured between terminals, Ohm:

• "A" and "B": 50-65;
• "C" and "O": 50-65.

Vacuum sensor

The sensor is mounted in the engine compartment on the front shield and is connected by a hose to the intake manifold at a point located after the throttle valve. The sensor provides control over the engine load.

Voltage at terminals, V:

under vacuum, kg/cm²:

• 0,2: 3,5-3,9;
• 0,6: 1,3-1,7;
• 0,8: 0,3-0,7.

Coolant temperature sensor

The coolant temperature sensor is a resistor with a negative temperature coefficient, i.e. its resistance decreases as the temperature increases.



Sensor resistance at coolant temperature, kOhm:

• -18°C: >15;
• -7°C: 7.3;
• -4°C: 6,5.
• 20°C: 2.95.
• 38°C: 1,45;
• 70°C: 0.5;
• 100°C: 0,325.

Exhaust Gas Oxygen Sensor

The sensor ("lambda probe") is installed in the exhaust pipe and sends signals to the controller about the oxygen content in the exhaust gases.

Vehicle speed sensor

The sensor is an inductive type, located at the exit of the speedometer drive cable from the gearbox and sends a signal of the vehicle speed to the controller.