An update on this guys...

So yesterday I tried disconnecting the above mentioned sensor (on the underside of the inlet manifold) and it made no difference...

I filled coolant in the van and tried to start it again, again nothing...so I did the usual trick of spraying some brake cleaner into the throttle body, quickly ran inside and started it...as usual ran spot on...

However, this time, I let the van continue to run for around 30mins, revving, holding rpm etc...ran well...fan came on a number of times, bled the cooling system etc...

So I thought let me turn it off and try start it....and somehow, it started!!!

I turned it on and off around 10 times and it started every time!

SO im wondering if the coolant had anything to do with it...

One other thing I have noticed though...is it idles high...around 1.8k according to the rev counter...checked for air leaks and couldnt find any from a quick look

I disconnected the ICV and the revs drop back down to normal but it will eventually cut out after maybe 5mins or so...as soon as I reconnect the ICV, the revs go back up to 1.8k

Could a faulty idle control valve be causing this or is something else causing it to behave in this way?

Thanks for all the help so far!