W126 stumbling before stopping
 

Hello out there!
Ok so I got a rebuilt fuel distributor and replaced the thermo-vacume valve which fixed the rough idol, at rest. However, when coming to a stop right before actually stopping the car feels as though its stumbling and stuttering with the rough idle returning briefly until it comes to a complete stop then catches itself and smooths out.Also, there is no hesitation off the line and cruise is flawless but seems to lack power going up hills. So...any suggestions?
1990 420 SEL.

Thanks in advance

Sounds quite like a failing fuel distributor.