The electrical characteristics of the elements of this electronic fuel injection system and the ignition system were obtained using a universal measuring instrument, to which specific automotive functions such as speed sensor, fuel injection time, oxygen sensor, etc. were integrated.
Before diagnosing, be sure to check:
- engine start system (battery, starter and wires);
- quality and availability of fuel in the fuel tank;
- exhaust gas recirculation system;
- air supply system (tightness of pipes, gaskets and various fittings), air filter and thermostat in the filter housing;
- accelerator cable for the absence of a slow return to its original position and full throttle opening;
- crankcase ventilation system;
- tightness of the fuel system;
- compression and engine condition;
- spark plug;
- fuse for the electronic fuel injection system and the ignition system.
The diagnostic procedure should begin with a fault analysis (symptoms).
Pic. 5.23. Arrangement and numbering of contacts of connectors of the control unit: A - with a manual transmission; B - with automatic transmission
The contacts of the electrical connectors are indicated by a number with a letter, for example, pin 1A - pin No. 1 of the electrical connector A (pic. 5.23).
Checking the electrical supply of the electronic injection system
All electrical power tests for the electronic fuel injection system and the ignition system must be performed with the connectors connected, with the exception of the engine control module connector. Tests of check are resulted in tab. 5.2.
Checking the electrical resistance of the sensors
All sensor electrical resistance tests must be performed at the engine control unit connectors. The tests are given in table. 5.3.
Checking the electrical power supply of the sensors
All tests to check the electrical supply of the sensors must be carried out at the connector of the engine control unit. The tests are given in table. 5.4.
Checking the elements of the fuel supply system
Checking the elements of the fuel supply system is given in table. 5.5.
Checking the general electrical supply of the electronic fuel injection system
All tests to check the general electrical supply of the electronic fuel injection system must be performed with the connectors connected, with the exception of the engine control module connector. The tests are given in table. 5.6.