Now you might think that spraying lighter gas approaching a hot engine isnt wise, however the flash /ignition tapering off of gas is virtually 400C as a result you compulsion a naked flare or spark to set it off and Ive used this method for many years without incident. appear in your way through each feasible joint one at a epoch and you should locate it. I use a slightly flattened fragment of brake pipe and some rubber hose from the can of lighter gas to find the money for a spraying wand and allow a concentrate on blast of gas into each area, especially those hard to accomplish next large implements.
Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can reach a quick oddity locate if you unplug the meter and control the engine without it. if the engine condition is the similar subsequently chances are the meter or the membership to it is faulty. Its plus worth cleaning the MAF sensor wires, as they can get coated behind dirt exceeding times which then offsets the reading. Use some open cleaner or brake cleaner to vaporizer onto the wires to remove the dirt upon no account adjoin the wires past all as they are very fragile
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you going on 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 going on and is warmed up? oftentimes in engine put it on many factors may cause the same symptom(s)