Bad ground = high idle RPM?

[Phax]

I recently swapped out my USDM tach for a JDM 180SX tach. At the same time, I wired up boost, A/F, EGT and oil pressure gauges. Once I got everything put back together, I noticed that the car consistently idles at around 1100-1200RPM, where as it used to idle at 800RPM. I also get shocked on the way out of the car sometimes, when I touch the driver's side door.

Would an improperly grounded connection cause a higher idle RPM?