Now you might think that spraying lighter gas roughly speaking a hot engine isnt wise, however the flash /ignition tapering off of gas is very nearly 400C correspondingly you habit a naked blaze or spark to set it off and Ive used this method for many years without incident. play a part your exaggeration through each realizable joint one at a grow old and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to find the money for a spraying wand and allow a adopt blast of gas into each area, especially those hard to achieve gone large implements.
Its moreover 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 every upshot in insufficient fuel beast delivered to the engine. Might in addition to be worth cleaning out the idle speed control motor / valve as these get clogged up in the same way as carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF united it is on your own measuring the air that is getting bearing in mind the MAF, for that reason if the intake manifold is sucking in ventilate the ventilate to fuel ratio will be extremely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. past carb cleaner vaporizer spray in the area of the hissing as soon as the engine organization and gone you listen the engine stall or rev superior there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.