MPI and MPFI injection system Gasoline consumption Audi's high-tech engines also get a little help from electronics «curb thirst» engine. At cruising speed, the Audi can get by on 8.5...
Additional MPI/MPFI Functions The MPI/MPFI is a very expensive injection system whose control unit additionally controls the electronic ignition. The MPI/MPFI injection control unit is...
Injection system components In order to better understand the functioning of the injection system as a whole, it is first important to learn about the tasks of its individual components....
Function of the injection system Coordinated work of individual parts When the engine is running, pistons that rise and fall in the cylinders suck in air. If you fully depress the gas pedal,...
Adjustment with lambda probe The catalyst can work efficiently only when the relative amount of air λ (lambda) as close as possible to 1. To achieve this, the MPI/MPFI ignition/injection...
Malfunctions and self-diagnosis MPI/MPFI The MPI/MPFI control unit can recognize about 30 defects in the electrical components of the ignition/injection system and store them in the computer's memory....
Self-diagnosis of the injection system Mode of action Unfortunately, many types of checks are not available to the amateur due to the lack of the necessary control devices. Nevertheless, there is...
Visual inspection of MPI/MPFI injection system 1. Check the air hoses for leaks. All hoses need to be checked - from the thick air intake hose to the small vacuum hose from the pressure regulator. 2. In the...
Checking injection system components The following sections describe inspections of injection system components that are possible using amateur tools. Injection valves If there is a suspicion that...
Removing individual parts of the injection system Many parts of the injection system do not need an additional dismantling description. Exceptions are described in the following sections. Replacing the lambda...
Throttle cable Details of throttle control in the engine compartment of a six-cylinder engine 1 - nipple at the end of the throttle cable; 2 - throttle lever; 3 - throttle...
Idle adjustment All Audi A4 models have automatic idle speed control. The set screw is no longer there, with which nothing can be adjusted. If the idle speed is incorrect,...
Exhaust Gas Test Everything you need to know about exhaust gas testing can be found in the section Motronic injection system . Tip: Disconnecting the battery clears the...
Help with MPI/MPFI faults Malfunction Her reasons Your help A. Cold engine does not start or starts poorly 1. Defective fuse 13, 21, 25, 27 or 28 2. Faulty fuel pump relay 3. The fuel...