At minimum, you need to replace your engine wiring harness, coil wires, coil supressor boots, and spark plugs.

Only use the plain, non-resistor, Bosch copper plugs.

I would do a thorough search on posts by Arthur Dalton. He is surely the #1 authority on diagnosing problems with this engine / chassis.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".