Hey Steve:

Here is another post that I wrote when I checked the figures from my EHA:

"Hey guys:

I've read around on the posts here and learned a few things thanks to all, but I am a little bewildered on how to set my mixture right on my car.

From what I read, people say I have to put an amp meter between the EHA and it should read 7 to 8ma current draw at idle if the mixture is set right. Someone also said I could check this also from pin #3 on the diagnostics port. Well, I went under the hood this evening and here is what I found:

a) I don't have a pin #3, its missing in the hole. #1 has about 8 volts or so, #2 0.0, #4 is 13.7, #5 is 13.6, #6 is 12.6 and #7 through #9 are 0 volts to ground when engine is running at idle.

I put the amp meter between the EHA, and it shows -0.14ma when engine is at idle. If I step on the gas, it jumps up to 4, 5, or even 7ma, but then quickly returns to -0.14 or so.

I found out that you have to push down in the aircleaner hole with a 2.5mm wrench and just before the engine dies it engauges and you can rotate the mixture setting. Makes the engine run slow and rough or smooth and fast. I played with it a bit but the amps remain at -0.14 at idle. I did readjust idle speed with adjustment screw when I played with mixture settings, but no luck with getting EHA voltage to 8ma. What gives and where do I go from here?

I want to get the mixture set right as my car is hard to start hot and I want to eliminate this as an issue. Dialing it in by ear seems to work, but I'd rather do it scientifically with a voltmeter if someone will be kind enough to tell me how to!

Thanks!

-=>Raja."

I will go search for "through the Captain" as you suggest to see what those words might mean. I drove the car today to work and it seems to hesitate slightly with part throttle (it feels like its missing or something) and I think now that I read some of the DIY information its hesitating around the 2k to 2500 rpms range. If I am on the highway I don't feel any hesitations - they only appear from 40mph to 60mph or so. If I throttle the engine up by hand while I'm under the hood, I can feel the engine "pulse" a little bit as its running say 2k rpms (no tach while I am under the hood). Idle is smooth, fast idle is smooth, 3000 rpms and beyond is smooth, just the midrange is not good. I'm thinking maybe its the mixture screw to fix that hesitation at part throttle?

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1983 MB 190E, bought from Germany and shipped to the US in 1986.