Thanks everyone for all the replies. The problem is definitely pointing to fuel pump --

I dug out my old generic scanner and found:

Live: DataStream
Fuel SYS1, OL, not ready CL
Fuel SYS2, OL, not ready CL
Error Codes:
P0171 Pd Generic System too lean (bank 1)
P0174 Pd Generic System too lean (bank 2)
P1083 BMW Fuel control limit mixture too lean (bank1 sensor)
P1084 BMW Fuel control limit mixture too lean (bank2 sensor)

When I turn key to run position, I don't hear any sound coming from under the rear seat, so seems like the pump is not running. The noise I mentioned was coming from under the plastic engine cover - I was able to track this down after realizing had the HVAC fun running, turning that off helped. I guess I will worry that later. May be the fuel system is trying to do something without getting enough pressure from the fuel pump. I watch a bunch of fuel pump replacement videos last night till very late, so task today is open up the access to the fuel pump and see if I get any voltage to it and if it is pumping fuel out.