The performance edge!

The first Tech Session of 2025, held on a sunny March 22, welcomed Porsche enthusiasts with open arms and springtime vibes. This gathering was more than just cars and coffee; it was an opportunity to connect, learn, and celebrate the passion for Porsches. Hosts Tom Vagi and Max Rundlett set the stage with coffee, doughnuts, and an intriguing display of used and new oil samples, cleverly disguised as honey jars. Topics ranged from the importance of service records and routine maintenance, like replacing pollen filters and brake fluid, to winter storage preparations. Even the smallest details, like overfilling tires and safeguarding against pesky mice, were covered with engaging clarity.

by Bob Tucker

There is so much mystery surrounding the CIS (continuous injection system) fuel system Bosch has dubbed K Jetronic, I wanted to try and make some sense of it for all Porsche owners. The bits of the system include the fuel pump, pre-pump on some models, fuel filter, accumulator, fuel distributor, warm-up regulator, injectors, auxiliary air valve, air sensor plate, cold start valve, thermo-time sensor and on newer models an oxygen sensor, frequency valve and mixture control unit were added.

If you think you're fuel pump is not working, here's how to check it out:

The Bosch K Jetronic, or continuous injection system (CIS), is a mechanically-based fuel injection system that was used on the 911, 911 Turbo, 924, 924 Turbo, and 928 models during the 1970's and into the early 1990's. As these systems age, there are several components you can change to tune up the system, which is what we'll cover, using a 911SC as the example. The components we'll look at are the in-tank fuel filter, the regular fuel filter, and the fuel injectors. Note that CIS fuel injectors have a non-replaceable filter inside the fuel injector.

Before looking at any add-on improvements to your suspension or tires, you should perform a detailed maintenance check on what you have today.