Hey guys ! i bought a CD9A Last years and didn't got the time to ride it ... when i bought it it were having a rought idle and problem with the transmission ... the guys who did it where not really trustable so i get out the engine .. make a little clean up off all and put it back ... No more rough idle and no any problem but one

it starts well but stay between 1200-1500 RPM and when it wad ... we check any boost leak and theres not ... the wastegate seems good ! we check the IAC ... the sensor of the throtle body and while running we deplug it and pu it back and nothing change ... no idle drop or anything ... does it seems to be that or maybe i got something else !?!

 

its common for the idle air screw to back out. causes high idle . idle speed motor wont be able to correct. there is a rubber plug on top of throttle body. (if it hasnt been lost ) under that is the idle screw. the oring dries out with age. allows the idle screw to twist out on its own.