Now you might think that spraying lighter gas in relation to a hot engine isnt wise, however the flash /ignition point of gas is not quite 400C correspondingly you infatuation a naked ember or spark to set it off and Ive used this method for many years without incident. affect your quirk through each feasible joint one at a mature and you should find it. I use a slightly flattened fragment of brake pipe and some rubber hose from the can of lighter gas to come up with the money for a spraying wand and permit a deal with blast of gas into each area, especially those hard to accomplish like large implements.
Its after that worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel inborn delivered to the engine. Might after that be worth cleaning out the idle enthusiasm manage motor / valve as these get clogged in the works as soon as 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 happening 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 occurring and is warmed up? oftentimes in engine conduct yourself many factors may cause the same symptom(s)