if its carb (been awile since seen under hood of one) clean carb with carb cleaner and change fuel filter. if EFI, change fuel filter and run some fuel injector cleaner. also cheak air filter, if engine starves for air it wont idle. if it set awile gas could be bad. theres a gas aditive called sea foam you can get at a parts store. use this with a bottle of outlaw octane booster and itle fix the problem with the gas. only other thing i can thinlk of would be the idle control valve mabey need adjusted but try this last. hope this helps.