From your description, it sounds like it is running on two cylinders. You wouldn't be the first to cross a couple of ignition wires. Have you checked to make sure this is not the case?

Maybe you are overlooking the obvious. That's exactly what I do when I get frustrated with one of my cars. Step back and remember the basics, It only takes three things for an IC engine to run -- Fuel, Compression, and Spark.

Sounds like you have fuel, even to the cylinders that are not working properly, based on your comment about the strong fuel smell. You can pull the plugs from cylinders 1 and 2 to confirm that they are fuel soaked if you like. You may need to change them anyway.

You should check the compression on all cylinders if you have not already done so.

Check the ignition timing and confirm that the timing belt has not slipped.

Check for spark to the cyliners 1 and 2. You can use a timing light, or if you don't have one handy, a neon bulb with one lead grounded should work.

How long has it been since you changed the distributor cap, rotor and ignition wires? I pulled a rotor out of a '90 240 I bought a while back and the resistor element was almost completely eroded. Note also that the two cylinders that are giving you trouble have the longest ignition wires. Maybe you have two much resistance and these cylinders just wont fire correctly. This can happen with new or almost new wires. (Weak Coil???)

Good luck,

Dan