While driving truck lost power and shut off

My little S10 lost power suddenly while going down the road. Engine completely shut off acted as if there was no compression whatsoever. Towed it home took the front end apart thinking timing chain. Open it up timing chain is in perfect condition there are no missing teeth from either gear and the timing marks line up just like they should. I'm not sure what else it could be. I've got spark, I've got gas. it backfired when I added starting fluid, but I still don't get any start, it cranks and cranks and cranks. What else could be the problem?