Check the hose clips for tightness and inspect the trunking for any cracks or splits and with all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best pretentiousness to find a leak is to have the engine management and warm and then spray can lighter gas /propane or brake cleaner roughly each joint in turn. If the engine rev s stirring you ve found your leak.
Might after that be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can reach a quick irregularity find if you unplug the meter and control the engine without it. if the engine condition is the same later chances are the meter or the connection to it is faulty. Its then worth cleaning the MAF sensor wires, as they can acquire coated bearing in mind dirt higher than epoch which next offsets the reading. Use some door cleaner or brake cleaner to spray can onto the wires to cut off the dirt upon no account adjoin the wires in the manner of everything as they are definitely fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you up to date upon all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms stirring and is warmed up? oftentimes in engine work many factors may cause the same symptom(s)