High guys anyone here encounter my same problem? I cleaned my throttle body and replaced new iacv. When my car is running my idle kicks at 1300 sometimes it goes 1500 even if it is in neutral, and goes to normal when i fully stopped the car. Honda civic 2000 model manual transmission

Please help!!

 

The ECU will increase the idle speed of the engine based on coolant temperature (higher idle for colder engine). Are you still having this issue on a fully warmed engine? I believe that the ECU may also raise the idle speed slightly on a moving vehicle vs. a stationary one.

 

DaX is correct here... and when the increased idle speed values get as high as you have described, it is likely that you have a cooling issue as well. Air bubbles trapped in the cooling system will cause elevated idle speeds while moving.

 

Ok guys thanks for the info, lately i replaced my coolant and also replaced the radiator cap and bleed the cooling system. I will try to run it and observe if my idle goes high again while running. I will update you guys thanks a lot.