My "won't rev up" problem on my 88 carbed might be a vapor lock, has anybody had experience with this problem, it comes and goes and when it's doing this I can't even drive it home, then after messing with it for hours and hours and days and days, all of a sudden it works and I think I have it fixed and then it does it again a few days or a week later, over and over again, I'm afraid to drive it now.