I checked my battery with my awesome free voltmeter from Harbor Freight and I got a reading of 12.71. From what I understand, that's a normal reading.
I checked the sweep effect in the options screen in the left gauge and it's turned on.
I checked my oil level and it looks normal as well.
So I fired up my Z for the first time today a few mins ago and everything was normal again. I didn't feel the engine shudder at start up and the gauge effects was operating correctly.
Yesterday, I got home from work and did some stuff around the house. Then I went out an hour later to run an errand. After my errand, I hopped back into my car, fired it up and noticed the engine shudder and gauge effects not working. I thought nothing of it and went straight home. When I got home, I decided to see if I could replicate and record the engine shudder and non-functioning gauge effects. Sure enough, the engine did shudder and the gauge effects wasn't operating.
So this leads me to believe that this problem happens when the car is warmed up/hot. After I got home from work, my Z was still warm when I went out on my errand. Then when I finished my errand, my Z was still warm when I noticed the problem. I get home and tried to replicate the issue and sure enough, it occurred again.
Cold car = no engine shudder, working gauge effects
Hot car = engine shudder, non-working gauge effects
So do you guys have any other ideas what this could be?
I'm going to try cleaning my throttle bodies per this thread here:
DIY Clean your Throttle Bodies - MyG37 It looks simple enough to do. Do I have to remove my stock factory strut tower bar in order to access the throttle bodies? I want to remove as few parts as necessary.