OK, My 1988 420 is still being troublesome. Minimal use for last 3-4 years before I purchased in August. I have replaced fuel filter, fuel inlet line, spark plugs, rotor and distributor cap, idle air valve, fuel pump relay. The pump relay got the car running down the road again. Now, as long as you stay easy on the gas, below 30 mph, the car runs great. Step on it to go above 30 and the engine wants to stall out--like running out of gas. Let up on the gas and everything is fine again. Also at issue--since I have had the car--it WILL STALL when you make a right turn, and only turning right. Shove into neutral, the car restarts instantly, and away you go--till the next right turn. I am thinking the sock/filter in the bottom of the tank? Crud in the bottom of the tank? Fuel guage fluctuates between empty and full--never know what it is going to show until I start the car, and then that might change while drving. Can the sending units be cleaned/repaired? I am new at Mercedes ownership and repair, so please help! Thanks, Steve