ICV issue

[John1.4]

the ecu does do a self test yes, but as parts deteriorate it adjusts to the new values for sensors over time, the calibration from those 'self tests' is held in a type of flash memory, which needs to be cleared after new parts are fitted which don't 'match' with the stored calibrations - the ecu assumes the expected values will remain the same, and doesn't know what to set the icv position to (for example) hence the high idle

the icv's are not all the same as above, there are 3 distinct types for the TU series, with different bolt patterns, and iirc one has a slightly larger diameter