Since I bought my new to me w124, Its had a bit of a rough idle, but runs and drive fantastically off idle. It surges/ pulses as if it has a vacuum leak. I picked up one of "ricks scanners" (a blink type scanner) and pulled the codes just now. In looking at how much they vary, I'm curious as to whether or not I have just a bunch of little issues, or potentially one root cause.

I have to admit, I tend to prefer Japanese made vehicles, and the w124 is almost like chinese to me. That being said, I'm a competent mechanic and really just looking for some seasoned opinions before I dive in. (also its ~ 3*F outside right now, So i'd like to spend as little time dicking around with it outside as possible :P )

first, A bit of info about the vehicle. It is a 1993 300E, m104, 3.2L, RWD, AT with 167k.

The codes I pulled are:

6 - 3, 5, 8 (air bag codes, not all that concerned with them ATM..)
8 - 4, 13
14 - 3, 5, 11

Which breaks down to
8-4: Load Sensor in EAL/AKR control module faulty
8-13: Full load contact does not open
14-3: Cruise control/ Idle speed control actuator
14-5: Stop lamp switch (third brake light is out, Will this set this code?
14-11: Fuel Safety Shut off to LF-SFI control module

SRS codes
6-3: Driver Airbag Squib
6-5: Airbag/ETR, Driver seat belt buckle switch
6-8: Voltage supply interrupted

Now, I drove it to work today.. Cruise control works fantastically. To the best of my knowledge, the cruise control is a vacuum operated system on these cars, Meaning that if I had a vacuum leak.. The system wouldn't operate as intended. I suspected the idle control valve, and the EGR as possible culprits, but lack of EGR codes and a good hydrocarbon reading from the tailpipe leads me to believe that the EGR is not the culprit.

Which brings me back around to the IACV. My first step, baring all these things are not related to one lousy ground, ETC. Is to pull the little sucker and clean the hell out of it.