high idle

That's the recirc valve /dump valve .
It would be the small vac pipe for it to cure idle issues as that is post throttle
I'm assuming Cedric has already checked for leaks ???? If not check all the small pipes coming from the inlet manifold and also the idle valve pipework to throttle base .
I know the fuel reg has been messed about with so double check that has a good seal .

Yes it was that small vac pipe.

I'm assuming Cedric has already checked for leaks ????

well i havent for a while, last time was a couple of months ago one of the fuel pipes returning from the left bank back to the fuel regulator was split so i replaced it. havent noticed anything recently but i havent inspected either...
i will check again.

What happens when you unplug the idle valve ,hot or cold ?

on hot engine, i disconnected the plug and nothing happened for about a minute then the engine revved up... connected it again and engine went back down instantly. is that what it's supposed to do? havent tried on cold yet but will do this weekend (well when i manage to get in the car because i left the lights on and the battery is now completely flat which means that i cant unlock the car! again! ).

i have checked the new old water temp sensor on cold engine the resistance is 293 ohms and hot (about 90 degrees C) 414 ohms. so it seems to be ok according to Clee's values page 1 of this thread...

i wil check for the coolant pipe an throttle pulley too

thanks all for your help and support

Oh dear I gave some false information earlier in this post.

I provided a photo of the engine bay of a GTA Le Mans pointing to a component and saying a split pipe caused a high idle, well I got the wrong part. I was at the time talking about the engine on my Venturi but I did not have the Venturi at my home or a photo of the engine bay to refer to and was limited to my defective memory, so now it is time to correct my error.

The photos show the position of the small hose on the Venturi engine and the engine bay. I am sure Clee would be able to identify the component the hose is connected to.

Sorry for the duff info.