Vintage Cars: c126 380 question, vacuum leaks, fuel pump relay

Question
My c126 1984 380 sat for 4 years. Was not getting fuel so I change the fuel pump (got on ebay) started car but it idled hi from 12 to 1800 rpms was going to change the idle valve but when to start it the next day and it seems the fuel pump is out again. At this point I'm thinking I should check something else a rely or something do you have any ideal how to trouble shoot this issue..

Answer
there is a fuel pump relay, look in your owners manual it is a large fuse block  BUT ....are you getting fuel delivered? Can you hear the fuel pump,could be lots of things for a car that sat for 4 years.  Have you changed fuel filter?  How old is the gas?
Vacuum leaks, plugs,
Give me a bit more detail to see if I can help
Ron