Hi, does anyone know what the CIS control unit does? If this is a computer control unit that determines speed, fuel/air mixture, throttle control etc, would it be posible to upgrade my cars engine and performance via this method? I mean using a CIS from a later model, better performance model? This unit is listed in a parts mag. but gives no discription as to what it does or is for. My baby is a 1985 190E 2.3 8V. Thank you.

CIS controls the fuel metering system (injectors). Accepts a number of inputs from ECU, temp, air flow sensor, etc. Don't think what you are suggesting is the best way to go about improving performance. Each unit is designed to work with a particular engine application, so other than getting a new replacement, not much will change. Whatever you get will have to be designed to mate with a four banger. There may be performance options out there, but I am not familar with what's available for the 2.3. You might consider getting a 16v and swapping engines. Maybe you could ask Benzmac. He has a lot of good experience with these engines.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

Thanks for the reply. I was just curious as I have never heard of this part before. I will do as you suggestion and leave it the heck alone. Thank you again.