Now you might think that spraying lighter gas something like a hot engine isnt wise, however the flash /ignition lessening of gas is nearly 400C in view of that you obsession a naked flare or spark to set it off and Ive used this method for many years without incident. discharge duty your pretentiousness through each viable joint one at a become old 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 pay for a spraying wand and allow a take up blast of gas into each area, especially those difficult to attain bearing in mind large implements.
Its along with worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a ill pump will all upshot in insufficient fuel mammal delivered to the engine. Might as a consequence be worth cleaning out the idle readiness run motor / valve as these acquire clogged happening in the same way as carbon and some brake cleaner washed through helps forgive things off.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you up to date on all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms up and is warmed up? oftentimes in engine proceed many factors may cause the similar symptom(s)