We purchased a 1985 380 SL with 64k miles in May.
The car has problems with primarily hot restarts, occasionally cold starts.
The prior owners replaced the fuel tank at 52k and the fuel injectors at 53k miles. (We suspect a fuel contamination issue)
Maintenance we have performed so far:
Clean the idle air valve, car now idles smoothly at 500 rmp after warming up (seemed very rich until warm)
Replaced cold start valve and thermoswitch. Car runs smoother during warm up.
Still had hot restart issue (seemed lean)
Read multiple threads here and on SL forum, especially re accumulator.
Leak tested accumulator- it leaked, a lot
Replaced accumulator, fuel pump check valve and filter.
Car usually starts fine, both hot and cold starts.
But:
When starting, you sometimes get a fair amount of black smoke (exhaust pipe). I am sure the valve seal leaks a little but this smoke does not smell of oil. Also, for about a block, if you press the accelerator hard (not slamming it but just pressing it), the car bucks and you get a big cloud of black smoke. After a block, no problems, car runs great.
I do not have a pressure tester and am unwilling to replace other parts without more knowledge. Any suggestions?
Also, saw a reference to the thermovacuum valve. What exactly does this do?

Check the fittings at the warm up acccumulator, at the front of the intake manifold (2 fuel lines going to it). Mine had similar symptoms and one of the fittings had an orifice in it which was clogged (dirty). I removed the orifice and it ran fine. I ordered a new fitting from the dealer and it didn't have an orifice in it (?). Car runs great now so I don't worry about it

EDIT: I just noticed the date of this post; oh well, maybe it'll help someone

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1983 380SL
1995 C280
1995 S500 coupe
1990 Mazda Miata
2004 Suzuki Hayabusa