Remove this ICV valve clean it out, with white spirits , or car cleaner.. And look for splits in the connecting hoses both of them that come off it.,And any splits in vacuum hoses you can find in the engine depot The fuel distributor sits on a large rubber gasket or boot more like it .These are a known problem ,and split along the base . Do you have a econometer in the console [speedo] if so what is the econometer needle sitting at when ticking over?At engine tickover the needle should be bang over to the left . If its sitting in another possition ,you have a vacuum leak.