I have a 1970 FJ40 with the original F motor. I recently rebuilt the carb, and when I started it it wasnt running right. The carb guy said he rebuilt the carburaetor to exactly wat it was when it came in. I adjusted the timing on it to the best I can. It backfired and cracked my exhaust. I brought it to my local shop, and they said they cant adjust the timing, because they have never seen anything like it. When they put it to stock specs, it wont run right. I just got my license last week, and havent been able to drive it. The mechanic thinks its the vaccum, or the speed controller. I am going to take it back tonight since they have had it for a week. Does anyone have any experience with this problem, and if soo, what can i do to fix it.