rough idle and sometimes cut out,

[daymo69er]

on idle it idles around 1300-1400 rpm which i know is high but if i play with the throttle cable and loosen it so it goes down to around the 600-700mark it cuts out,

also when i accelerate it seems to have hesitation when i change gear as the revs dont seem to drop very quick when put clutch in? ,

any ideas guys on what this could be? , or anything i can do to try sort it out, bit embaressing if pull up to lights and car just cuts out, :\ , starts fine but just not sure what it could be,

ive cleaned throttle body, checked the elbow from the throttle body for holes / rips just not sure what it could be

any help would be good:) , or if anyone is down plymouth way and fancy a look would be appreciated!

[Speedtouch]

Try letting the car idle with the engine warmed up, and spraying WD40 all around the inlet manifold gasket (from above and below); if it briefly raises the idle speed then you have a gasket leak.

Also check all inlet manifold/TB hoses for splits.

[E30-Doc]

sounds similar to when my Throttle position sensor went. This would be worth a check
( i did all the usual hose leak chasing, and ICV cleaning, and replaced all my gaskets to find it was the TPS all along)... things ran a lot smoother after all the work

[DanThe]

If it wont idle with the throttle shut you clearly have vacuum/secondary air problems