I suspected an air leak initially but am now fairly sure it is not that. The car runs absolutely fine when cold, and even when initially warming up. It idles smoothly and revs freely. I would expect an air leak to show up all the time, or at least once everything had warmed up a bit.
The change is almost like a switch being thrown between smooth running and spluttering once it is thoroughly warmed through. It is this switch like change that makes me think it is a sensor that is playing up.
ECU read temp and air flow, decides it cold and uses one mapping. Then decides it has warmed up and wants to adjust the settings but is getting bad info about airflow so it over-leans the engine.
I will have a play tomorrow when I will hopefully have some daylight. I plan to drive it until it starts spluttering and then return home to try
1) Disconnect MAF, start car and see if the problem stops.
2) Reconnect MAF, start car and see if the problem returns.
3) Swear profusely when nothing makes sense and torch the fricking thing!!!
Any better suggestions?
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