300CE-24 misfiring

[Ross Speirs]

I have a continuing problem with my 1989 300CE misfiring and cutting out after reaching normal running temperature. The fault only occurs when the car has been left standing for more than 4-5 days; and the fault only developed about nine months after I bought it. I believe it's caused by vapour from the sump getting into the distributor (cleaning the inside of the distributor head with a moisture dispersant solves the problem in the short term).
Does anyone know what might have caused the fault in the first place, and what can be done to cure it? Any help would be greatly appreciated.

 

[television]

If the amount of condensation is high, have you checked to see if there is any water in the oil, this can be seen on the dip stick or filler cap as small water bubbles.

malcolm