I really need help installing a tachometer in my car, like if there is a pictured diagram of this, i'm a computer nerd. not a car wiz

Welcome to the forum. You will need to connect the signal wire for the tach to one of the white wires coming out of the 6-pin connector on the ICM.

http://www.grandamgt.com/forum/attachment.php?attachmentid=3884

The Ignition Control Module is located below the coil packs.

in the plug with 6 pins. There is a missing wire next to a purple-white wire. we tryed to put the tach on that but it didn't work.

I don't understand what you mean. Try plugging it into the slot labeled "121 WHT ==> TACH SIGNAL"

It's just-above the dead center of the picture.

the picture isn't showing up for me

http://img327.imageshack.us/img327/1898/icmwiring8be.jpg

There ya go

I found the wire i need, but it isn't just hanging there, it is with the rest in some type of jacket that goes to the PCM. Do i need to just put that wire out of the jacket, or out of the plug. or cut it