the prob is when i shift gears the idle wont come down it always stay in the 2000-4000 rpm in neutral still rolling(10 mph+) then when i stop (0 mph) the idle come back to normal then if i go to 10 mph and more the car goes into fast idle like 2000rpm-4000 in cruising mode and wont come down i cheked for leak and tb cable ,iac everything look fine

my engine is a b18c5
thx for helping

 

double check cooling sytem level and air pockets. tps voltage, and idle motor function. good luck