I mention this system in another thread and just incas no-one knows what I'm rattling on about, here's a brief description I poached from another site.
All european 924's are fitted with Bosch K-Jetronic (k-tronic) continuous injection system (CIS) fuel injection. Although known as the k-tronic system it does not depend on electronics, but on the passage of air through a sensor plate. The system provides constant fuel output at the fuel injectors which is varied by the position of the sensor plate in the air stream. As air passes through the airflow meter, the sensor plate is lifted from rest. The sensor plate is connected to a pneumatic arm and the angle at which the sensor plate becomes stable depends on the airflow which is governed by the engine speed. The sensor plate pneumatic arm directly operated the fuel metering unit. The sensor plate arm moves a plunger in the metering bores of the metering unit (one for each injector) increasing or decreasing the injector fuel flow as required. The bores are specially machined to provide different air/fuel mixtures at different engine speeds. The Bosch k-tronic system is a most reliable and easy to trouble-shoot system and is central to the 924's well known reliability.