About

Bosch K-Jetronic seems to be a bit of a black art these days. Almost anyone you mention it to backs off and cringes. Hopefully this series of posts clears up some of that misinformation and scaremongering, and opens more people up to working with their KJet instead of binning it, or neglecting it until it inevitably fails.

First things first, what is K-Jetronic?

In simple terms, its a form of mechanical fuel injection.

In more elaborate terms, KJet is a Continuous Injection System (commonly called CIS), where unlike later L-Jetronic or “standard” Electronic Fuel Injection, the injectors do not pulse open and closed; once the system pressure is high enough they all inject a constant spray of fuel, in all cylinders at once, which is varied in volume by the system depending on various factors.

Kjet was used from the 70s, into the mid 90s, and was primarily used on European cars. Mercedes, VW, Audi, Porsche and Ford were the more prolific brands to use it, and when it worked, it worked well. It was used on many different engine configurations, displacements, and even on Forced Induction engines; it’s quite flexible.