Fuel injection system - testing and adjustment
Testing
1. If a fault appears in the fuel injection system first ensure that all the system wiring connectors are securely connected and free of corrosion. Then ensure that the fault is not due to poor maintenance; ie, check that the air cleaner filter element is clean, the spark plugs are in good condition and correctly gapped, the cylinder compression pressures are correct, the ignition timing is correct and the engine breather hoses are clear and undamaged.
2. If these checks fail to reveal the cause of the problem the vehicle should be taken to a suitably equipped Vauxhall dealer for testing.
Your dealer has access to special electronic diagnostic equipment which will locate the fault quickly and simply, alleviating the need to test all the system components individually (a time consuming operation that carries a high risk of damaging the control unit).
Adjustment
3. On 1.4 and 1.6 litre models, whilst experienced home mechanics with a considerable amount of skill and equipment (including a good-quality tachometer and a good-quality, carefully-calibrated exhaust gas analyser) may be able to check the exhaust CO level and the idle speed, if these are found to be in need of adjustment the car must be taken to a suitably-equipped Vauxhall dealer for testing. Neither the mixture (exhaust gas CO level) or idle speed are adjustable, and should either be incorrect then a fault must be present in the fuel injection system.
4. On 1.8 litre models, both the idle speed and idle mixture (exhaust gas CO level) are adjustable.
5. On 2.0 litre models not equipped with a catalytic converter the idle mixture (exhaust gas CO level) can be adjusted, however the idle speed is regulated by the control unit and is not adjustable. On models with a catalytic converter, both the idle speed and mixture (exhaust gas CO level) are regulated by the control unit (see paragraph 3). Should the idle speed/mixture (as applicable) be incorrect then a fault must be present in the fuel injection system.
Test yourself
A quick Opel Corsa quiz: every answer comes with an explanation and a link to the manual page.