No slow when engine is cold until when engine is hot

When I try to start it comes on and doesn't do slow until I stepped on the throttle and the engine is hot with few movement then the engine won't go off and will do normal slow both at park and drive. Multiple machine detects all 4 cylinder misfire but plug and ignition coil has been replaced still won't do slow when engine is cold! This has really cost me time and money going from one mechanic to another. Please what is the possible solution to my car not doing slow when first stat but until the engine is hot and has moved some distances.