OK but check this out too, Search on patrick_mb to see his two threads on M103 W126 part thottle mixture adjustment. He did a great job of explaining what to check and measure the mix. He also explains what you do with the EHA current.

He explains it a little differently and that helps me alot. He describes going too far rich and too far lean and watching the O2 sensor output while driving. I've watched the ratio but not the sensor.

What I was getting into was how to measure the current at the EHA. To do it your meter needs a current range and I just realized I have a clamping amp meter attachment for my cheap radio shack multimeter. The connector in on the gas distributor drivers side back corner. Black plastic thing with a two wire connector that pulls off towards the rear. With a clamp on, you don't need to rig up a way to get into the circuit to measure current.

Basically you open one of the two connections and the meter remakes the connection. I used some banana plug leads. Just find a way to connect one side with a jumper and connect your meter bewteen the other two. Choose 1Amp range first for the .75 A at Ignition switch on, then down range to see when you start the engine and want to see the +-.1A

I had to clean the gutters today (yes dear) so I didn't get a chance to duplicate what patrick-mb did.