hi john, thats a good idea, ill add an earth to the turbo..
i have a little update, yesterday chris sat i nthe car looking at the aem whilst i pulled sensor plugs out.. here are the results:
1.) map sensor.. --> car dies.. good it means this one works lol
2.) water temp.. --> engine check light comes one.. so it means its giving a reading.. ie good
3.) single wire water temp sensor.. --> works well
4.) iat.. --> removed.. i dont get any engine warning light, doesnt affect idle in any way when warm or cold
so it could be the culprit.. my only worry is why the hell doesnt the ecu light start flickering.. if the ecu is still getting a ground signal from this wire if say its earthing out.. would it mean that its getting any random reading from where-ever is touching? (not sure if that makes sense to read but its the best way i could explain it...)
im gonna add a few earthing points this week maybe it will change something, ost of my old earthing kit seems to have served its time & needs retireing lol
kon