This car has to be in flood mode in order to start easier. When stopped from driving the engine shakes and idles bad for a second then goes back to normal. Minimal hesitation in acceleration. Putting your foot down on the accelerator the engine seems just fine with no apparent backfires or misfires. This vehicle also sat for 7 months and may have had lost of battery power for some time. There may need to be a PCM reset? Also is there any way a coolant thermostat have anything to do with it?