1983 European MB 190E, how do you adjust mixture? - PeachParts Mercedes-Benz Forum

rbort · #1 03-31-2004, 10:39 PM

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.

rbort · #2 04-01-2004, 04:46 PM

Does anyone here have any insight? I was anxious to find a response to my post as my car is in the garage, the hood is up and I'm up here looking for answers on what to try next. I was disappointed to see no responses to my post.

If anyone can help, please do! Anxious MB owner looking for a "misson" to accomplish on the car this evening --- I need something to do please!!!

-=>Raja.

mike65 · #3 04-01-2004, 04:57 PM

190E 2.3 mixture adjustment

Mike.

rbort · #4 04-01-2004, 06:31 PM

I am reading the Bosch Mixture adjustment document now. It doesn't relate 100% to my car (no pin #3) but I will try to make as much sense of it as I can. Then I'm off to the garage to exercise what I've learned on the patient!

-=>Raja.