Ford Repair: Backfiring 1984 Ford Ranger, ford ranger, gas tank

Question
I recently bought a 1984 Ford Ranger with 60000 original miles.  It idles fast and burns really too rich (when I attempted to turn back the idle, the engine wanted to stall).  It has started backfiring on the downshift or when decelerating.  Where would you begin to diagnose the cause of the backfiring?  Sometimes it is just a soft popping, but sometimes it is a gunshot!

Answer
LaDonna, your problem has the characteristics of a vehicle that is out of time.  I would first try to adjust the timing by loosening the 'pin' or 'key' on the bottom of the distributor (basically just a tab that holds the distributor in place).  With the engine running, slightly adjust the distributor until the engine rpm's come down.  My guess is that you will need to "retard" the timing, but go ahead and try turning it both ways.  If this doesn't help, then you may need to remove the timing cover and inspect the timing chain.  Now, assuming that timing is not the problem, the next thing I would do is rebuild the carburetor.  You might also try pouring a bottle of Heet into the gas tank.  I hope this helps,   Jason