ooooh whereabouts in the world are you?
self diagnosis is easy
just follow the link
http://toyota-supra.info/forums/showthread.php?t=323
let us know what codes you come back with
i would probably imagine air flow meter by the sounds of it
but ya... let us know what codes you get and we'll be happy to help
p.s. good spotting there Tony
i'm so used to the term bonnet i didn't even realise it was out of place haha