RV8 Pilot reported on short final an aircraft taxi onto the runway resulted in taking evasive action and a NMAC. Pilot also reported taxing aircraft had radio problems.

Narrative

I announced my intentions to enter the traffic pattern for RWY XX at ZZZ [airport] and entered at approximately 6100' MSL at XA55L from the south on 45 to the left down wing. While I was downwind a Cessna announced their intentions to take the runway to takeoff and I said that I would extend downwind to let them get out as I had noticed 2 to 3 airplanes holding short. The Cessna said they thought it would be no factor but I opted to extend because of the high approach speed of the RV-8. I made a left base call when I saw them departing. While on approximately 1/4 to 1/3 mile final; a Super Decathlon; announced they were pulling on to and departing RWY XX. I could see them rolling towards the runway and as soon as they were done transmitting I keyed the mike to tell them I was on short final. They did not stop nor did they respond on the radio. I announced that I was going around on RWY XX and offset to the south over taxiway 1. I used only partial power and left my flaps down for longer than normal so I could keep the Super Decathlon in sight and safely deconflict flight paths. When approximately abeam the numbers XY I asked if the Super Decathlon was still on frequency and by this time was co-altitude on their 9 o'clock. They never answered. I opted to add full power at this point and accelerate away from them on upwind for XX and then made a cross wind turn. Another aircraft in the pattern remarked that they thought the Super Decathlon had radio problems because they were not able to hear or reach them on the ground.