I have a 1998 GS300. I purchased it 3 months ago. It hadn't run for over a year, but started right up after I replaced the key cylinder. I am having trouble with it stalling out when idling. It had the spark plugs replaced and idle adjusted up a bit. I have been also adding injector cleaner. It is worse when the engine has been running for greater than 30 minutes. Any input or ideas would be greatly appreciated. Thank you 😊

 

My first thought is the gas may have gone bad from it sitting for that long. Did you drain and put fresh fuel in before starting?