1986 Euro 190E 2.3-16 Suddenly Running Really Rough - Any Suggestions?
 

Good Evening,

I recently turned my 1986 190E 2.3-16 over to my son, with 206,000 miles on it. He was washing the car today after school, and I heard the car running as he moved it into position to be reached with the hose. It sounded like it was running on 3 cylinders, so I took it out with him and drove up and down the local sections of I-95.

Once it showed over 80 degrees C on the oil temperature guage, I let it run to redline in second and third gear. While it will rev, it has no real pop. The gas pedal feels soft and mushy, not sharp and responsive. After some full throttle, high rpm runs it seemed to be a little better but not much. When you start from a stop it still acts like it is not running on all four cylinders, really rough and lots of shaking. The first tip in of the pedal nearly stalls the engine, then it picks up and starts to follow the pedal movement. But not like it usually does.

I checked the distributor cap and rotor, which seemed to be pretty heavily tracked with carbon and other burned metal deposits along the rotor conductor and the distributor cap conductors. This rotor and cap have been in there for at least 100,000 miles. I cleaned them carefully, and cleaned out the cap aferward. I did notice a pool of oil in the depression in the distributor, under the little black plastic shield, and I cleaned that up with a paper towel.

The car starts, idles at the correct speed (1,000 rpm +/- 100 rpm or so, but it is steady), but also suddenly gets really poor mileage. I put in some fuel system cleaner, but that takes a while to work. Should I check the injectors? They are the same as came with the car, and have never been out of the little bosses they fit into. How do they come out? Can I just start the car with one out at a time and check the spray pattern? Any suggestions and tips on doing this would be appreciated.

I figure it is time for a cap, rotor, new plugs, K&N air cleaner (has a stock unit in there now that is due to be changed) anyway. Are there any other tune up things to address with this car? Should I use Platinum plugs or Copper?

Thanks in advance for the time to read and respond. Jim

I would have the ignition system checked to see if you lost a resistor tip. They are under the plastic cover.

Benzmac,

When you say they are under the plastic cover do you mean they are under the plastic cover that the spark plugs and wires are hidden by? Are the resistor tips in the connectors to the plugs?

I hate to sound so ignorant, but I figure it is better to ask then start taking things apart without a clue what I am really looking for.

Thanks again, Jim