Check the hose clips for tightness and inspect the trunking for any cracks or splits and moreover every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best showing off to locate a leak is to have the engine supervision and hot and later spray lighter gas /propane or brake cleaner vis--vis each joint in turn. If the engine rev s happening you ve found your leak.
Its as well as worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a under the weather pump will all repercussion in insufficient fuel inborn delivered to the engine. Might as a consequence be worth cleaning out the idle speed run motor / valve as these get clogged in the works with carbon and some brake cleaner washed through helps release things off.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you in the works to date on every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms taking place and is warmed up? oftentimes in engine proceed many factors may cause the thesame symptom(s)