89 supra 7mge bought it with a bad headgasket and just put a new one on it after its been sitting for a year and a half. I've have the following problems: when you first hit the gas fairly sudden it pauses then kicks in also it dies sometimes when you hit the gas sudden. When driving it runs fairly smooth but has random points where it studders. Temp gauge stays under half but the car feels like it is running at 6500rpm when it only shows it at 4000rpm. It idles at 800rpm and starts right up everytime. Still smoking white smoke dont know if its from coolant still in the exhaust or the pauses and hesitation. Would bad gas cause this to happen? Looking for any suggestions or comments.