98 W140 miss on uphill acceleration only
 

I have a 1998 S320 W140 which runs like a top except for one issue. If you are cruising down the highway at 50 or 60 and start up a hill and slowly accelerate so that it kicks down, and hold your foot right there, she will start missing.

If I accelerate from a stop, hard or easily,no miss. If I accelerate from 50 or 60 on the level or down hill, no miss. Accelerate around a corner, no miss. Only misses under that one specific condition, up a moderate to steep incline under kick-down acceleration. Cold or warm out does not matter.

New plugs maybe 20k miles ago. Ditto for one of the coils, the rest tested ok.

This problem sound familiar to anyone ?

Probably the connectors/boots under the coils that go onto the spark plugs. Look closely where the connectors meet the porcelain of the plugs for graphite like powder, if it is present the connectors are the problem.

I prefer basic original plugs vs upgrades. A new set of wires with plug connectors may be the best way to go.

Good luck!!!