The car is a 1999 pontiac grand prix with a junk yard motor thrown in, I know the previous owner and the car will shut off on occasion, especially when the car turns left. Sometimes it starts back up, sometimes it wont. Not the alternator, or the battery. All the connections seem good and tight. And now the motor has a faint tick in the back center cylinder that comes and goes but then knocks under throttle. The girl Im helping keeps bringing it back to the previous owner but it doesnt have any problems when he drives it so Im trying to do what I can to help. Any help would be greatly appreciated. Thanks.