Can someone explain me why this happens?

I own a lancer 2.0 ,2012 , 4cylinder , stick shift

  1. Every time i accelerate and decelerate, the engine jerks and the rpm hops.
    When its going in 4th or 5th gear and i leave accelerator, the engine falls down like someone is trying to stop the car.
  1. When i start the engine on cold start, it revs up to 1800 rpm and then slowly goes down after 5 minutes.
  1. When i switch on the AC, car goes like someone pressed the brakes and slow acceleration.
  1. It was totally fine when i bought it, but i pressed the race and drove harshly, which lead to some ticking sound in the engine, i gave for fix and it got fixed but then all these problem arouse
  1. I really love this car, someone please tell me how to fix it?

I did tune up, changed spark plugs, cleaned throttle body, changed clutch plate, clutch bearing, clutch pressure, air compressor.

No. 1-2

Changed it, same issue



do pressure test the fuel pump and pray it's weak, cause often on those the engines just flat wear out when older and revved too high and then need rebuilding