96 Ram 1500 318 Cid

My Dodge RAM back fires back through the intake , mostly when it is cold; however, lately it has backfired when at operating temperature. I have changed the plugs to no avail. The cap, rotor and wires have about 20k miles on them. I have also installed a JET power control module in the truck. Has anyone run into this backfiring problem? If so, HELP! By the way, Thanks LTJG Worth. I found my vacuum leak right at the cruise servo. A 6 inch piece of rubber hose solved my problem! I am retired Navy.

Backfiring would only be cause by bad timing, or really bad valves. Have the timing checked out. That is probably what the problem is. Retired Navy? What rate/rank did you make?