SSP 121 – MPI in the 20-valve naturally aspirated engine

 

INDEX

A high-performance engine variant in the Audi 90 and Audi Coupé range is the 2.3-liter engine with four-valve technology. This power unit is a further development of the 2.0-liter five-cylinder 20-valve engine.

The fully electronic engine management system MULTIPOINT INJECTION (MPI), in combination with a three-way catalytic converter and lambda control, ensures compliance with U.S. exhaust emission standards.

The new version of the 20-valve naturally aspirated engine described here (engine code 7A) can be identified at first glance by the modified idle air control valve and the cast exhaust manifold.

Contents

  • Part I – Important fundamentals

  • Power diagram

  • Major innovations

  • Overall overview

  • Engine components and connections

  • Fuel system

  • Ignition system

  • Idle air control

  • Fuel tank ventilation system

  • Crankcase ventilation

  • Exhaust gas recirculation (EGR)

  • Power supply

  • Self-diagnosis

  • Part II – Important details for troubleshooting

  • Part II begins on page 26 with a table of contents