Recently went and played around in some sand/dirt hills...truck now has issues when accelerating and feels like loss of power as well.

main question: what could happen if sand has entered my engine?

 

if you got a lot of sand in your air filter that could cause a loss of power i think, as for accellerating issues, need to be more specific: is it jerking or just slower accleration?

as for sand getting past the airfilter and into the engine i'm not sure what would happen.

 

slight jerking...the air filter was replaced right after the run

 

could be dirty fuel filter

 

This might be a shot in the dark, but were you running extremely high RPMs while you were screwin' around in the sand? I had a similar experience many years ago. It turned out that I was running abnormally high RPMs on spark plugs that were just about dead to begin with. My mud run finished 'em off. The truck ran like crap right after the fun. Replaced the plugs and all was well.

Might be worth checking.