Well, I am finally enjoying my "new" E320. A 94 with 24,000 original miles was giving me fits with it's surging and "limp" mode.

Did a complete wiring harness... which the car absolutely needed, but unfortunately that repair did NOT fix the problem I was having.

Anyway, the bottom-line is that I did a lot of studying. My mechanic talked to a lot of other shops that work on older cars like these, and ended up talking with a couple of real "experts" (!) Anyway, everyone's first guess was that the car needed a throttle actuator rebuild which we ended up doing.

Sent it out to Beckman Technologies and for right around $1100, they sent us a rebuilt unit (compare to $2000+ for a new MB part.) As you know, other guys rebuild them for about $500, but Beckman has the reputation for doing the best and most complete rebuild. One shop in Florida told my mechanic that he has 55 gallon drums in the back of his shop FILLED with throttle actuators from E320's and he has a pile of wiring harnesses 10 feet tall behind the shop. He said this is the problem 99% of the time.

Incidentally, my guy cut a slit in the wiring harness that comes off the throttle actuator and opened it up just for grins. He couldn't believe the condition of those wires! He told me they were all cracked and split exposing bare wire. There were black carbon-like deposits inside and it looked like it was caused by possible sparking, arching and so on. I was tempted to do a manual wire replacement job... one by one, but decided that I just wanted the problem to be over so we did the rebuild. (all this on a perfect car with an engine compartment you could eat off of) Amazing... the deterioration of the wiring...

Hope this helps with others struggling. It was a serious pain in the A**, but the car is a perfect specimen and a joy to drive. Between the harness, the Throttle Actuator, OVP Relay and a few other things we did, it cost me about $3000 to get the car right, with only 24,000 ,iles, I'm hoping to get many years out of this car.