This is a '93 400e with some 128K. Originally started having intermittent power loss while accelerating, which later escalated to very rough idling. No check light, no problems starting.

Replaced ignition cables, plugs, rotors and distributor caps. No effect.

Replaced upper wiring harness. Idling is OK now. Acceleration OK for a few miles then starts acting up but not as bad as before. Feels like half of the cylinders are off.

Any suggestions would be appreciated. I'd like to avoid replacing the large wiring harness if at all possible.

Alex

'93 400E
'95 SL500
'90 RR County (yes, i am a masochist)
'99 RR 4.6 HSE