my husband bought a 1993 F150.he put a new motor in changed the alternator new wiring harness new MAP sensor put on truck still doesn't run. idles fine starts fine as soon as you hit the ga it trys to stall and sputters and backfires. any ideas would welcome thanks

 

Welcome to the forum. I assume the engine is a 302 or 5.0L. With the stalling and backfiring involved, I would definately look at the distributor timing, fireing order, (plug wires crossed) things of that nature, look there first, if all is good get back to us.

 

Sounds like firing order is off. So check to make sure proper wires go to proper coil/spark plugs coil packs ... whatever the configuration.