Got back onto sorting the Megane idling problem. Changed all the manifold gaskets, all new injector rings - absolutely no vacuum leaks.
Thought I heard the alternator squeaking, so swapped that thinking it might have a seizing bearing. nope.
Today I bit the bullet and swapped all the ECUs id kept from the old car. Engine, body module, key card reader and electric steering column lock as theyre all coded to each other. Big job... Lots of time with the laptop reconfiguring things because the ECUs came out of an automatic and this one is a manual - so a lot of time finding the menus and telling the body module it was in a manual and to start without in being in Park.
And it runs soooooo much better - so the fault all along was the ECU. It ran fine when I last turned it off, but i guess maybe i dropped it or something...
Anyway, but not all good news. It idles smoothly now, but high at 1000rpm, not the 750 it should. I "think" that will resolve with a few miles of driving around.
But the problem now is the cooling fan runs full tilt all the time... The engine ECU is authorising the AC and is running the fan, but the climate computer is not asking the engine ECU to do that - so thats a problem.
And the engine ecu is throwing a code because it cant see the auto ECU anymore.... I have no idea if the fan and the lack of the auto computer are related.
Every singe ecu on the car I can change the configurations - i can tell the body computer its in a manual now, i can tell the ABS computer what its in. Even the climate control module i can configure. But not the fucking engine one...
So I've learnt two things - i spent a shitlaod of time and money chasing every engine fault under the sun when it was the ecu all along. And I need to either get the original manual ECU repaired, or the auto engine ECU repaired, or buy another whole VIN matched set from a manual car...
So I guess its progress of a sort.