got this from someone i know.hopefully help anyone else out this happens to.
"had this happen a few times in various cars, predominantly in the winter, never a plesant experience.
usually caused by 3 things, moisture in the throttle body freezing and jamming it, though unless your intyercooler is absolutely immense, this is usually restricted to NA cars.(quite sure supra throttles are water heated anyways to prevent this)
crud in the throttle body jamming it or gumming up the bearings
finally an issue with the throttle cable or cruise controll cable (where fitted)
detach the throttle cable and have someone press the accelerator by hand while you pull the cable at the throttle, go back and forth, see if its sticking, if it is, replace it, dont be tempted to grease it up or anything, as youv discovered, it could kill you., next up is the throttle body, again, cable detached, swing the throttle through its fill sweep and see if it sticks atall, take the boost hose off and have a look inside, is it dirty? if its atall suspect, take it off, clean it with some carb cleaner, and try and get some light oil (like 3 in 1) into the bearings(too light an oil will jsut evaporate, like wd40, and to heavy an oil wont penetrate the bearing).
on supras teh throttle assembly is quite a bulky thing, with lots of stuff hanging off it, but if your methodical it isnt to hard to remove. if it happens again, source a decent second hand one and jsut replace it, one of the bushings the throttle spindle sits on could have abnormal wear and be binding as a result."