Kayuwong when I went through the electronics in my car thoroughly to trace the problem it was the ECU not sending proper voltage to my TPS, which sounds like the exact same for you, only way I could cure it was a ECU rebuild. I wasted a lot of money on mass air flow sensors, fuel pump, fuel filter, TPS sensor before these guys told me to check the ECU.

 

I just replaced all 8 caps for two bad ECU, one works perfect and the other does not. Any inputs beside bad caps? Car with bad ECU acts like before, can't pass 2000 rpm. It bother me that I spent all these time and can't pin point where there problem is.