has anyone ever lessened the spring tension in the expansion valve? I believe that our MB are utilizing less coils than we could in our evaporators. It makes sense that the factory spec springs are set very conservatively so that the evaporator doesn't ice, but we're also protected by the evaporator temp sensor. Since the TXV is regulated by pressure differential, diaphram vs spring, I believe a lessor spring tension would allow more refridgerant to get to the evaporator coils; that's what we want; especially in hot climates. I'm not talking about unscrewing the piece; but a modification. I don't want to send too much refridgerant through; I just want to maximize the superheat and I know it's not being done as good as it could be.
The ford scorpio's in europe have the same problem as our MB and they've worked out a solution with the evaporator temp sensor....I'm more interested in the spring adjustment. Check out their site.
All climates are not the same and sometimes one size just can't fit all does it?
http://www.fordscorpio.co.uk/acmod.htm