Jim911
While you are sitting by the fire and enjoying a few beers, we can go over a list. Concentrating on the carb back fire.
Reasons for carb backfire listed in the order they most frequently occur.
1. mixture too lean
2. timing too far advanced
3. spark plug wires in the wrong order
4. intake valve(s) sticking open
5. spark occurring at the wrong time
6. poltergeist
7. other
Before we make a list of reasons for each, a few questions about today.
A. The engine was running without shutdown and restart before you went to drive out?
B. You opened the garage door and let in 27 degree air?
C. You put the clutch in and put it in gear?
D. You started to move the truck?
E. At which one of these points did the backfire begin?
F. Did the engine continue to run after the backfire? If so was it smooth Between backfires?
G. You didn't leave the vacuum gauge connected?
The answers to these will establish the time line of the problem. Then we will look for the zebras.
