Optra rpm problems. anyone, please help

[Maxell00]

hi, i bought my optra 1.6 in May 05. now at 8k already. the problem now is with the rpm. in a few occasions, when the speed is around 80 km/h and i let go of the accelerator, the rpm will move up and down a few times between 2 and 1.3. i don't think that is normal.

 

also, on a few occasion and getting more often now, the rpm will stay at 1.5 for a few minutes when i let go of the accelerator and even when the car is on neutral.

 

sometime the accelerator pedal would feel stiff and not smooth. if i press a little harder, the accelerator will jump from 1.1 to 2 straight and hard to maintain at 1.7 which the car speed at around 40-50km/hr.

 

anyone know what is wrong? i brought the car to the dealer and they say there is nothing wrong with the car. they detected some errors with the computer error detection system. reset the system and the car will be ok for a few days and the problem would re-surface. anyone can help. thanks

 

also, anyone know how to make sure complain to GM? have been very disappointed with the car.

[Elfenstar]

If its only the meter (i.e. the engine does not feel that its rev hunting) then its just the sender to the tacho.

 

If its the engine, there are heaps of possible reasons, from a small vacuum leak, to faulty air-flow meter, to faulty o2 sensor, to incorrect AFR's, faulty idle control sensor, ... Rev hunting is not normal. as the mech to tell you what error/s the fault self-diagnosis revealed then we can see where to go from there.