BenzMac.or M.B. Doc,..or anybody else with some insight

Heres something to ponder..my 420sel benz runs great for about 20min, then the idle goes rough on me and it spits and sputters down the road. Cap = O.K. Rotor = O.K. Wires = Just replaced. Area has High Humidity, but also wonder if the wires may be bad already. Idle control relay??, but why would that affect engine while on highway? Maybe water in gas due to high humidity??' but would that take 20 min to kick in?

Also does what is the timing specs for the 420sel and is it with or without vacume attached to distributor.

I would be looking at lack of voltage from coil and/or lack of fuel due to weak pump when hot, possibly a crankshaft position sensor that flakes out when hot? Just my thoughts.

As for timming specs, the ignition control unit takes care of that (12 degrees BTDC ?) and there should not be a vacuum line to the distributor.

[Edited by MB Medic on 07-21-2001 at 01:16 PM]