I i have a acoord lx 1990 and i have a idle problem. My idle up and down 1000 to 2600 rpm. It always happen even if the motor is cold or hot. I hace change the eac alve ant the fast idle one ans nothing change. In the beggining this proble happen only after i have start the car and disapeared after 30 sec but today it happen always. If i release the clutch in 1 gear at low speed it happen to.Please give me some advise. Thanks and have a good day

 

have you cleaned your throttle body/injectors/fuel system? changed your o2 sensor lately?

 

Ok take you throttle body off. Then look for a metal plate on the back side of it nearest the firewall. Take the 2 screws off with a 8mm. Then tighten that plastic pice in their with a flat head. Their should be like a spring loaded ball with a plastic thing around it. When that vibrates loose it causes it to have erratic idle. Bc you already changed eac and fast idle its gotta be this. Also try turning the idle screw clockwise. This fixed my idle

 

I didn't understand where you tighten the plastic thing. Is this in the throttle angle positionner? The only plastic thing i have see in this is the pin who maintained the throttle. But the only way to reach this is to remove the sensor and its riveted in the body. Thanks for the advice. Have a good day.

 

Yeah i have clean my throttle body and my o2 sensor is new.

 

The only plastic piece on the throttle body. It is behing the metal plate that has 2 screws on it.