Kmurphy

Got in my truck one morning, instantly started acting like it was out of gas, backfiring, loud as hell, weird gas smell, stalling out, then ultimately not starting at all. I've replaced: spark plugs and throttle position sensor and changed the oil. The shop replaced: Crankshaft position sensor, battery, terminals, fuel pump, replaced and or reprogrammed the ECM. Now they are saying it's the timing. I'm at my wit's end with this truck I'm not convinced it's the timing considering he's been wrong on everything else. I'd like to think it's fuel related, but to be honest I'm totally clueless as to what's going on at this point.