Jetronic

Jetronic is a form of engine management, responsible for controlling the fuelling and occasionally the ignition of early E30 engines. It was superceded by Motronic in 1987.

Overview

Jetronic is an analogue engine management system which uses a number of sensors to measure the condition and performance of the engine in order to manage fuelling, all controlled by a simple ECU. Ignition timing is governed by a mechanical distributor, which was regulated by a number of mechanisms to advance or retard timing. The ignition timing is completely separate from the fuelling, unlike the later Motronic management which combined these two features.

The system fitted to the E30 is a variation known as L-Jetronic, which superceded the earlier K-Jetronic system that had been fitted to the E21. L-Jetronic was fitted to the M10 and early M20 engines, and went through a revision during its production years, meaning there are two versions of L-Jetronic fitted to E30 engines. These differences were to solve issues such as idling and cold starting, and used different components to solve these issues.

Jetronic is now seen as an inefficient and unreliable system, due to its reliance on mechanical and vacuum-driven components which can wear out over time. For that reason, we recommend converting to Motronic 1.3.

Components

The following components are specific to Jetronic-equipped vehicles. The information here supercedes any other details of components outlined in the Wiki, especially regarding Ignition, Fuel and Intake.

ECU Codes

ECU Number	System	Models	From/To
0280 000 318	L-Jetronic	318i	1983 - 84
0280 000 330	L-Jetronic	318i	1984 - 87
0280 001 301	L-Jetronic	320i and 323i	1982 - 84
0280 001 309	L-Jetronic	Later 320i
0280 001 308	L-Jetronic	Later 323i
0280 000 310	L-Jetronic	Late 323i