Trailtech Vapor installation problem

I installed a Trail Tech Vapor computer on my 08 te and the rpm is bouncing from 900 to 1840 at idle. The stock speedo reads 1850-60 consistant at idle.
I tried rapping the rpm signal wire more and less as per the instructions but still can't get a good reading.
Has anyone tapped into the stick rpm signal wire. Or does anyone know which color wire it is that connects to the stock computer or which number on the stock clip?

Thanks