to clean the air inlet paths around the injector shrouds. Got hold of a Bosch manual on how the KE-Jetronic system operates. Interesting stuff. I did not know that the injectors are mounted in those shrouds for two reasons, 1. to keep heat soak away from the injectors to avoid bubbling in the fuel and the accompanying hot start problems, and 2. to allow meatered air to pass directly past the tip of the injector (mainly at idle). This allows MUCH better mixing of the atomized fuel to take place. Instead of large globules of fuel, you instead will see a very fine mist. Obviously this mixture is a lot better for the combustion process. For a while now, I have been trying to figure out why there would be an extra air inlet leading from the ISV inlet pipe to the injectors, now I know! The last time I pulled the injectors out I noticed just how gunked up those air passage ways had become. Maybe now I can finally solve the rough idle? Will post again and let you folk know if it works.