Tag Archives: Mercedes
Bosch K-Jetronic injection system, in several guises, was a staple of petrol engines for almost 20 years. Starting from 73, millions of cars from across the spectrum, carried one form or another of Bosch venerable system. A quick, non exhaustive list, will include cars from Porsche, Mercedes, BMW, Audi, VW, Ferrari, Volvo, SAAB, Rolls-Royce… the list goes on.
Millions of those cars survive, and most are quite desirable ones. However, age takes its toll, and several problems are more or less endemic. A high sensitivity to vacuum leaks is one of them, difficult to troubleshoot, but fortunately easy to fix. More worrisome is the dependency on the Warm-Up Regulator (WUR) working perfectly.
The WUR is kind of a simple analog computer. Charged with varying the fuel pressure, and hence the A/F mix, it does so based on engine temperature and time. Later versions, also changed the mix according to admission vacuum. Being purely mechanical it’s reliable, but with enough time everything is finite: springs quit springing, diaphragms get punctured, etc.
A few of the part numbers can be still be found new, most can also be rebuilt by a few specialists, but wouldn’t it be nice if you could bring the WUR into the 21st century ? By giving it an electronic brain, it would allow its characteristics to be altered and fine-tuned, and maybe, some new tricks could be added ?
UT has tried it in the past, but there was some lack of development and they’ve been silent for some time. In the last months, Steve from Reanimotion seems to have taken the flag. An aggressive development schedule with heavy data logging seems to be making a difference to the end result. That, and the clever idea to use the proven MicroSquirt line of ECU’s. That decision freed him from an additional complex sub-project (a special purpose ECU) and enables many possible enhancements for the more crafty people out there.
For those concerned in keeping the period appearance of the engine bay, only needing to replace the WUR is also a plus. Visually, nothing else changes.
Steve will start to take orders shortly.