Your problem seems like something i had in my 660c suzuki wagonR. I got the tapporlt cover repair because center tappets were stuck. After i got that all done. Throttle was really bad, it constantly got stuck, so my mechanic unscrewed the tps (idle sensor) nd adjust that. That fixed the problem but after that my car got so worse, my mileage dropped from 17 too 12. Khair i noticed at 2700-3000rpm. If i slowly accelerated my rpm dropped back to zero, like engine would start/stop. I stabilized my foot at 2800rpm. Nd noticed rpm dropped to zero nd returned to 2800. Im lahore so i went to many mechanics, all are so stupid. Everyone said the MAF sensor is faulty, some said throttle body needs to be changed. Last week i got my launch CRP123 obd scanner. Connected that and adjusted my TPS sensor. TPS sensor is what controls everything, from idle to max power, even the steering hardens if the idle is not perfect. All my problems are fixed and i got my 17kmpl back. Dont know if it was helpful or not for you
