Hi, Re: Mechanical FI systems. If it makes anyone feel better, I don't think MB built any two MFI the same on all the 220SE thru the 280SE/SLs(a million or so engines). Of the 30 or so I've owned, no two had the same H/W- i. e. throttle valve, solenoids, relays, linkage, sensors, etc. The same relays were wired differently from year to year. Their, MB, literature reflects their attempt to solve the problems inherent in an analog system. The digital brain came later- at affordable cost.