Are there two fuel pumps on
 

a 1991 560 SEL? Is there a check valve on each of the pump?

I am planning to replace my fuel filter, fuel pump check valve and fuel accumulator as part of PM as well as to improve a hard starting issue. Upon reading shop CD pages and studied under there, I am pretty sure I got two fuel pumps.

The car just would start on the first turn, except right after shuting down. Today I had to turn twice to get her going with just a 45 minutes parking. There is not sign of any leak from EHA and I have not pulled "bleed line" off pressure regulator yet. looking at the other end of "bleed line" at the valve cover return, I could see some liquid. Should that line be bone dry or little condensation is o.k.?

I also opened one of the fuel lines to an injector from the top of fuel distributor and there is no fuel coming out. If I read it right, I should have at least 45 psi pressure 30 minutes after shutdown.

Yes,each pump has a valve.