I tuned a auto bolt on, cam camaro with dual 90 setup on it. It starts sometimes perfect other times it will die out. I started it like 5 times in a row then the 6th time it may die out. What could I check? Also another weird thing it does....I had the car idling for 10-15 mins perfect smooth at 800rpm and then the car started surging a couple hundred rpm for a few seconds then went back to 800rpm. This happen a handfull of times over several hours.