B2200 Sputtering /loss of Power

I have a 91 B2200 Mazda truck, with sputtering problem on acceleration and also I notice in temp guage flucuation.I have no Idea what is causing the problem. So far I change fuel to a Higher octain no results,Any Ideas?

Im running a 91 B2200 Carb, I also unpluged the pressure sensor located on the passenger side, with worse results. I'm hoping its just a carb problem. I have 111,000 miles on the vehicle. Again sputtering on accerlation and some temp sensor, up and down. To me it sound like I have multiply problems possible thermostat issue too.?

Tune the truck up with new plugs,wires ,rotor button,PCV valve.Get some carb cleaner and spray down the carb throat with engine at fast idle.Your sputtering will probably go away.

Thanks, found out it was a back up cat coverter, and bad carb. Guess im going to covert it to a Weber.