Action method
The control unit itself cannot be checked by amateur means. In practice, malfunctions are very rare in this node. Sensors, switches and wire connections give incomparably more reasons to complain. Therefore, in the event of a malfunction, the following procedure is recommended:
- If the check engine light is on, have the fault memory read by a workshop.
- If the check engine light does not come on, but there is still a problem, check if the ignition is OK.
- If the ignition system is OK, check the fuel supply. If the defect is not found here either:
- Carry out a visual inspection of the injection system components (see next section).
Visual check
In the event of a leak, so-called secondary air enters the area of the suction system, i.e. air that is not included in the calculations of the control unit and therefore significantly disrupts the process of preparing the air-fuel mixture. The mixture leans uncontrollably. Violation is most noticeable at idle by fluctuation in the number of revolutions. At full load on the engine, this can also lead to ringing.
- Check the vacuum hoses for cracks and tightness. All hoses on the injection module or on the exhaust manifold must be checked (e.g. intake air preheater, activated charcoal tanks).
- Warm up the engine while driving, and then let it idle, open the hood.
- Spray with starter fuel spray (For example, «Startpilot») injection module, flange to the intake manifold, gaskets for the flanges of the intake ducts and pipelines to the units with vacuum control. Disconnect the lambda probe connector so that the lambda control cannot work.
- If the number of revolutions changes when spraying a certain place, then a leaky area has been detected.
- Are there leaks in the fuel lines?
- Have you disconnected and reconnected wire connectors? Corrosion or unprofessional jerking can create poor contact.
- Carefully inspect the connectors of the individual injection units. Do not bend the contacts, just spray them with contact spray.
Visitor comments