need to start a process, first off temperature sensor and thermostat housing first off their is a recall on these worth checking with mini first off, lost count the amount of housing faults that have causes starting and running and intermittent faults, link below is for the new upgraded housing with the wiring cable it needs to change from 2 pin to 4 pin, dont be tempted to fit a cheaper one as they are rubbish, bmw/mini want £130 plus vat for one link below is a mini bmw saab parts specialist just mention if you do need to buy one i sent you off the forum as i'm trying to build up a rapport with them to maybe get the forum a discount at a later date, they also do good timing chain kits etc
https://www.ebay.co.uk/itm/Genuine-...653986?hash=item41d8e35f62:g:Q3UAAOSwgLlaXjxs
also knowing the cat and 02 sensors are happy and iff not why not most common on a 60k plus prince engine is stretched timing chain honestly check the chain tensioner distance before spending anything on it, that said the thermostat housing will one day let you down they all do,
another common thing is pcv valve in rocker cover or the pipework as a crack in it, a clue it when remove oil filler cap when engine idling if it dont make any difference to how its running then there is a leak, it should make engine idle jump around if all good, but still a smoke test worth doing, the other thing is diverter valve on turbo wears out 60-100k and when does it buts boost the ecu feels this and cuts fuel, as does the map/maff sensor these are one component held into the airbox just below the vvt motor on rear of head and is a proper **** to remove and replace,
live data runs are a must to see whether its misfires in one cylinder or all of them, if one then compression test it etc move coils and plugs around see if fault moves with it. i have lost count the amount of people who have replaced the high pressure pump to find later it was the chain its more likely to be the cain at fault and the sensors are reacting to this and trm fuel to the best it can,,
THE PRINCE ENGINE MUST HAVE 8K OIL CHANGES, MUST NEVER BE RUN ON LOW OIL UNDER MAX MARK 2-3MM ABOVE IS BETTER, this helps make them last ok on car with low oil have seen chains ruined and camshafts and head ruined under 24k, and car that have had oil light on last a few minutes before killed off