Need a KE - Jetronic expert

[Monomer]

I'm having some issues with my 83 380sel.


Currently:
-Cold starts are harsh. Studders for a few seconds, bringing up the rpm's cures this after a second. (It's now below freezing here in Michigan)
-Noticing less-than-great economy.
-No top end (nothing over 95; hell - my diesel was better)
- Idle in park = 1200-1300rpm; idle in drive - 900rpm
-o2 sensor is new, ICC is clean and lubed, Idle control is rebuilt, OVP is re-soldered.


Before I starting ripping into it all at once, what should I mess with first? Warm up regulator? Cold start injector? Mixer adjustment?


Someone help me!!!