Contents: Inlet air temperature sensor 🠛 Coolant temperature sensor 🠛 Engine speed sensor (flywheel) 🠛 Fuel injectors 🠛 Cold start nozzle - F7P engines…🠛 Idle speed control valve - F7P…🠛 Fuel pressure regulator 🠛
1. Renault dealers use special diagnostic equipment (XR25 unit), which is connected to the diagnostic coupling on the main casing in the car's interior. This device allows you to quickly and comprehensively diagnose the system. It is also the only means of checking the functioning of the processor unit.
2. The following points provide information on some checks to be carried out in the event of a malfunction.
3. The digital multimeter must be a modern type with an internal resistance of at least 10 megohms. Do not use analog devices (switch), which may have unacceptably low internal resistance.
4. Idle speed control motor, throttle potentiometer, manifold pressure sensor, vehicle speed sensor (where is it installed), or the processor unit cannot be checked in any way.
5. Before checking the serviceability of individual components, make sure that all system connectors are not corroded and are securely connected, and that all fuel, air and vacuum hoses are in good condition. Also remember that idle problems can simply be due to improper throttle cable adjustment.
6. If a defective component is found, replace it as described in next Chapter.
7. Do not attempt to adjust the idle speed with the stop screw on the throttle body. Please note that incorrect idle speed on this system may be due to errors or lack of signal from the vehicle speed sensor.
Inlet air temperature sensor
8. On D-series engines, the intake air temperature sensor is located on the front of the throttle body. On F3P engines, the sensor is located in the air duct connecting the throttle body to the air cleaner assembly. On F7P engines (with 16 valves), the sensor is located at the right end of the intake manifold.
9. Disconnect the sensor wiring. Connect an ohmmeter to the sensor terminals and measure its resistance. The permissible resistance is given in Specifications. Using a hair dryer, heat the sensor and make sure that its resistance decreases with increasing temperature.
Coolant temperature sensor
10. On D-series and F3P engines, the coolant temperature sensor is located at the front left end of the cylinder head. On F7P engines (with 16 valves), the sensor is located on the thermostat housing next to the temperature gauge sensor.
11. Disconnect the electrical wiring from the sensor. Using an ohmmeter, measure the resistance of the sensor and compare it with the value given in the Specifications. If the obtained value differs significantly from the given data, the sensor is most likely defective.
12. To accurately check the temperature range, the sensor will need to be removed. The testing procedure is similar to that described for testing the thermostat in Section 3. For resistance values, see. v Specifications at the beginning of this Section.
Engine speed sensor (flywheel)
13. With the ignition off, disconnect the speed sensor signal wire. Check the resistance of the sensor by connecting an ohmmeter to its terminals.
The result should be within 200±50 Ohms. Otherwise, replace the sensor.
[Text of the original source on this website: renaultbook.ru]
14. Using a feeler gauge, check that there is a gap of 1.0±0.5 mm between the end of the sensor and the flywheel. If the gap is incorrect, replace the sensor.
Fuel injectors
15. Remove the injector line together with the injectors, but do not disconnect the fuel hoses.
16. Place each nozzle in turn into a clean glass container. Turn on the fuel pump (see Chapter 8) and check that fuel does not drip from the injectors.
17. With the fuel pump running, apply 12 volts to the terminals of each injector one at a time. The injector should open and spray fuel into the glass bulb.
Cold start nozzle - F7P engines (with 16 valves)
18. The cold start injector is checked in the same way as described above for the main injectors.
Idle speed control valve - F7P engines (with 16 valves)
19. You can quickly check the valve as follows. With the engine idling, pinch or disconnect the air hose at the inlet side of the valve. The idle speed should drop. Once air flow is restored, the idle speed should increase and stabilize.
Fuel pressure regulator
20. Checking the fuel pressure regulator is covered in the fuel pressure check procedure (see Chapter 8).