Selrahc_5

Hello everyone,
I own a 1988 FC rx7 Convertible. Ive been having some problems for about 2 weeks now and i am stumped.... It is my DD and i haven't had many issues with it..
Car ran fine for 6 months, 2 weeks ago, it started having an issue with excessive backfire or afterburn. It sounded just a little rough at idle, but drove great. Went to work one day and started it after work and it sounded awful. I had to hold my foot on the gas to keep it alive for about 4 minutes till it warmed up then it would stay alive. The car was idling very erratically and bouncing.
Here is list of what i did

-New Plugs and wires
-Checked Compression
-Tested BAC
-Tested Coil Packs
-Tested MAP sensor
-Tested TPS
-New battery (Fried old one after compression test.)
-Checked vacuum lines

If you push the pedal to WOT fast, it stutters then shoots up. If you do it slower it goes up a little then will start to have issues, but it sounds fine most the time in the higher range, like theres no misfire....
The volt gauge in the dash is reading 0v, but accessories and all work fine.... If i hook a volt meter to the battery with the car is off its around 12.7-12.8, and on around 14.1.... Im not sure if these issues are even related, BUT this did start at the same exact time....

Thanks you for viewing my post!
-Charles