Poor starting/Stalling Vento 1.8

[boneybradley]

I am currently sorting a 1.8 vento out for a friend. this car has allway's being difficult to start when cold but recently we have changed the plug's and now when hot the rev's die and the car want's to stall. when you start the car when warm it rev's at 1100rpm and then drop's to 600 within a minute or two..also if you rev the car the rev's don't just drop straight down they seem to hover at 2000rpm and slowly drop to idle.
I am thinking ecu temp sensor but I don't have an idea where this is.
I do have a fault code reader but this dosen't plug into the same place (under the ashtray) as my mk3 8v.Any one know where else to check for this plug to connect this too??

any help as this is now beating me (and no car should ever do this... never mind a vw!!!)

[rubjonny]

ecu sender is in the plastic flange on the front of the head, if its an earlier one its a 2 pin blue, if late its a 4 pin.