We have an old but otherwise immaculate 28o S as a spare car. Right habd drive here in Southern Africa. Old engineering but good engineering, and would be sorry to see it go.
Problem is that it 'seems' to underperform. It is heavy and we are at 6000 feet altitude. Once going it is smooth. It is heavy on gas and exhausts burn vry dark grey/black on leaded fuel 93 octane. Merc mechanics shrug and say its old and we don't really know the condition of valve seals etc. It starts very easily. It gives a large puff of whitish smoke if the accelerator is depressed hard when travelling fast---say having had ones foot off the pedal for a few seconds and then accellerating firmly.
Other mechanics say that the carburettors on these cars eventually warp and proper settings cannot be achieved thereafter. Some say to convert to a Weber alternative that is OK but not quite up to the original carbs (A4 Solex, I believe). New Solex carb is abortively expensive for this car.
So much for questionable performance, but I was reading up on torque converters and there read about clutches in these devices that --if not functioning correctly--- can cost one 30% of power and gas overusage. Older auto-transmissions may be more susceptible to this. How would one check this?
Any tips or basic tests on 280S or effective ways or solutions to typical 'underperformance' problems (such as the carbs or transmissions) from any aspect will be very much appreciated. There could be simple things like throttles not opening fully, or some unexpected --but imprtant thing with these cars--like coils deteriorating in a benign way.
It is a pity that no effective English Language Workshop manuals (such as Haynes publications don't seem to exist).
I do look forward to comments with much interest and great appreciation.