Audi 80 Quiz
MPI and MPFI Injection Systems

Starting

In this manual: MPI and MPFI Injection Systems
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~1min read

Starting a cold engine requires an enriched mixture, i.e. one with a higher fuel content, because many fuel droplets condense on the inner walls of the injection system on their way to the combustion chambers and therefore do not take part in combustion. Therefore, the mixture must be enriched.


This is handled by the cold start program stored in the control unit memory. During cold start enrichment, for a specified number of ignition events, the injector opening time is increased. Injection duration is influenced by factors such as coolant temperature and engine speed. After a certain number of revolutions, the fuel quantity during cold start is gradually reduced to normal.

Test yourself

A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.