If after the above checks and adjustments no improvement in engine performance is noted, you should contact a specialized Renault service station to have the car checked. Using a diagnostic device connected to a special connector located under the ashtray of the central console, specialists display information about any unit of the injection system on the device screen. There are no combinations of error codes during diagnostics, so it is impossible for the car owner to independently determine a particular malfunction.
If the indicator lights up in the instrument cluster while the vehicle is moving "Injection system malfunction" or it does not go out after 3 seconds after the ignition is turned on, this may indicate a defect in the following devices:
- pressure sensor;
- throttle potentiometer;
- injectors;
- idle speed control;
- speed sensor;
- exhaust gas recirculation system solenoid valve;
- automatic transmission.
Some components of the fuel injection system can be checked by measuring their parameters, which are given in the subsection, however, the performance of a number of components cannot be assessed without special diagnostic equipment.
Experienced car enthusiasts with a tachometer and gas analyzer can check the CO level in the exhaust gases at idle. However, if it turns out that these characteristics require adjustment, you will have to contact a specialist for further checks using specialized equipment. Neither the CO level nor the idle speed are adjustable. If they are incorrect, the injection system is faulty.
Content of toxic substances in exhaust gases at engine crankshaft speed of (750±50) min⁻¹ and excess air coefficient of 0.97 < l < 1,03:
- CO* — no more than 0.5%
- CO₂ - not less than 14.5%
- SN - no more than 100 h.n.m.
* At 2500 min⁻¹ the CO content should not exceed 0.3%.
The toxic content test is carried out at a coolant temperature above 80°C after the engine has been running steadily at 2500 min⁻¹ for approximately 30 s.