Trouble finding Lambda and EHA current Range

[xp190]

Hi guys

I have a problem adjusting the fuel mixture in my 1985 190E 2.3L

I have just spent most of my day trying to figure it out, but so far no luck.

The car overall drives great, no hesitation, good response and everything, but I noticed that the economy gauge tends to lean to the right a bit while idleling in gear at a red light. This started happening after a timing chain change. The fuel economy is also not that great, and I noticed that when cold the car is a bit sluggish on take off, after 2K rpm, it flies.

So, I got my MM out and checked the lambda voltage. When warming up, it is a steady 4.0V, according to the manual this is correct, but when warm, the reading goes all the way up to 7.22V and stays there no matter what.

Similarly with the EHA current, on warmup, steady 8mA, once warmed up, it sky rockets to 16mA and won't come down at all.

Now from my previous reaserch this tells me that the mixture is lean, and the computer tries to compensate by enrichment.

I tried to lean out the mixture, I adjusted and adjusted but I get to the point when the engine bearly runs and neither the lambda nor the EHA current change one bit.

I had this problem before, but I managed to get things adjusted and the car ran great, it still does, but it seems to be running extremely lean and I can't correct this problem

I also went through the manuals checklist and made sure all the components function correctly. The MAF pot is a bit off scale, and I'm thinking of replacing it, everything else works just like it is supposed to.

Right now I'm really frustrated why I can't find the scale for computer to do what it is designed to, but I'm not sure if I'm missing something, or if it's the car.

Any suggestions to resolve this will be greatly appreciated.

xp