its starting to get cold here not too cold but colder past few times i started my camaro. she started up fine, i let it run few mins then ill press the gas and weird pop noise will do it about 2 times, then stop. ill take it for a drive runs fine. im inside the car so its hard to tell if its coming from back or the front i was guessing a backfire ? but not 100% sure. also when i go to start it takes lil longer than it was doing is this ok ?