Car runs without fuel pump relay!

I thought my car needed a new fuel pump relay so I went to my local parts store and bought one, and the weirdest things is happening. I connect the relay and the car trys to start but wont. Then I unplug the relay and the car will run, not good If I hold the rpms at 2500 its as smooth as silk, but I go any higher or lower it misses really bad. The car will run as long as I wont it to but then as soon as I plug the fuel pump relay back in it falls flatt on its face. I would like to know what is going on has anyone had this problem before and if so how do I fix it.

something is shorted somewhere. possibly in the computer?

Not sure if he still needs the info... he posted on two forums (not recommended) because he was in urgent need of help. But then he never responded to the help we tried to give him on the other post:

http://www.camaroz28.com/forums/showthread.php?t=584061