How do you adjust the timing belt in an 1994 Tercel that is not able to startcrank over and run?
Look where all the belts and pulleys are on the passenger side of the engine compartment. Way down at the lowest pulley. As you shine the timing light way down there, you will see the numbers 0 and 10 and the hash marks. You should see a notch on the pulley that you will use to line up the hash marks.
Adjust the timing. Backfiring is usually a sign that the car needs a tune up. The timing can be a big factor. Check the timing belt to see if it has jumped a tooth or two. If so, this is the reason why it would backfire. You also might want to check the tension pulleys to see if they are too tight or not tight enough.