I'm getting lousy mileage (a bit less than 20mpg) and have slightly dark plugs. I'm aware that winter mileage in Maine is normally worse than summer's. In an effort to improve the situation, I tried to open the MAP sensor to make adjustments there, but no dice - no way I can get the thing open without risking destruction. I experimented with opening a sensor from a later model and managed to ruin that one. After that I installed a pressure gauge in the cold start hose and adjusted the fuel pressure down to 28 psi. That helped a little. I remember George Downs talking about adjusting the ECU on one of his cars, but can't find the post back -- something about a button on the side or the back of the ECU that can be turned to lean the mixture. Where precisely is that button located and which way should it be turned? I'm in the process of intalling a set of Recaro front seats from a 325is BMW and have the passenger seat out, which gives me easy access to the ECU. So far, the only button I've been able to locate is on the left of the rear of the thing, next to the ribbed heat disperser. I that the one? BTW, I put in a set of newly refurbished injectors (CruzinPerformance) in the hope that that would inprove mileage, but it almost seems that the effect was the opposite.
Bob S.