I was asked to look at a honda 2003 type R that had an engine change due to the bottom end knocking.
The engineer who changed the engine is methodical and careful.
On start up the revs are 1800/2000 and as it warms up it starts to hunt.
smoked the inlet to check for leaks none found.
ran a diagnostic check no fault codes.
live data gave no clue apart from the s/t fuel trim was flicking between 98/1 with the hunting so it felt like an air leak.
cleaned throttle body still the same removed the idle control actuator and reset the idle spindle to idle the engine manually with engine running refitted the idle control and all is fine.
my conclusion is that the spindle must have flicked over during the engine change.
HAPPY DAYS