1991 190E 2.6 (baby Benz)
Major repairs and tuning of this car started with the fuel distributor being repaired by Larry of CIS Flow tech. Phone 215 929 3771, location is in southern Alabama, great person to work with he will take the time to walk you threw the set up.
I purchased the tool on line needed to set the upper and lower chambers of the fuel distributor, the only reason for that was that I messed up and got the EHA way out of adjustment and of course needed to make sure of the parameters of top and bottom chambers. Making the adjustments from 5.4 top to 5 lower was so frustrating because I had the EHA so far out that I had to find the center for the EHA balance, quite literally, turning the 2mm adjusting screw in to bottom and out making note of revolutions then setting the adjusting screw as close to half, or mid way of the EHA, this gave me a much closer setting for the 5.0 with just a few adjustments we had it spot on.
Now on to the rough Idle and miss, first thing done was to clean my plugs as they only had 6 or 7 hundred miles on them but to no avail, of course it made no change, the engine had such a rich burn that the exhaust was black and that was the reason for cleaning the plugs with a wire brush (brass) so new plugs, auto light 104 copper core and gap set at .30. Next I checked the plug wires all checked from 1.1 to 1.2 thousand, distributor cap from.580 t0 1.1 and rotor at .695, All I thought was good.
My next check was the potentiometer engine running it was at .5 good to go.
I placed a new ox into the system because of the over fueling and high carbon put into the exhaust system, the old died, the electrical source was putting 12.8 V into the heated ox, again good to go.
Still had that miss, so I pulled #1 wire and found a no change situation so I replaced the wires with new Bosch set and the miss was gone, now I have a well set power plant with very good power and the fuel mileage is 19 in town and 23 highway. Hope this has helped some one, if so great.
R&R fuel dis.
Plug wires
Plugs auto light 104
Balance upper and lower chambers of fuel dis.
Set potentiometer
R&R ox sensor
Clean distributor cap and rotor