Same ECU hota hai, eik hi.
For better economy, one should always shift gear at around 2000 rpms.
For jerks, check control arm bushes, also check play in axles aka goday.
Once again, wohi baat, first of all, make sure if the ecu is in there or not, only then we can guide you further.
Its like running an engine, without its brain. It cant sense anything.
Once again, JAZAK ALLAH. Such replies motivates me alot.