Low rpm at start, sometimes battery drains
I have a new problem on my 2010 Mazda CX-7 2.3 turbo petrol version. It's just crossed 130,000 km (80,000 miles).
About every 2 weeks / 1000 km, when I start the car, the rpm is about 700 even for morning starts. When the accelerator / throttle is floored, the rpm goes to 1400 max. After leaving it for a few hours, the battery can get totally drained and I have to jump-start it. When I jump-start it, everything is back to normal and the service centre can't find the problem. They mentioned that if there is a low voltage somewhere when starting it, it triggers the Throttle Positioning Sensor (TPS) which limits the rpm. No idea why the battery drains though.