Two questions

[70camaro]

Q1: How do I check the MAP sensor?
It is a 3 wire unit located on the firewall. I have a code 31, and manual doesn't say how to test the map. I'm guessing its a voltage drop measure, but I dont know which wires to test, and for what voltage.

Q2: Which wires in the diag. conn. do I jump to time this thing?
Manual says it should have a 4 prong conn. Well, mine has 5! Am I looking at the wrong thing??? Pretty sure it's the right conn., nothing's plugged into it and it's in the right spot... If anyone can give me the color of the wires that should be good enough (I'm assuming one is the blk/grnd).

B.T.W., it's a 94, 3cyl, w/ a 5spd.

Thanks in advance!!