I have a 93 Ford F-150 I just replaced the timing chain and its still not running right what could it be

When you installed the timing chain, it is a good idea to run the engine over several times and re-check the timing marks as sometimes turning it over 6 times will set it off a tooth when everything settles in. So, it could be a tooth off, if it was any more it would have hit a valve. The Camshaft Postion Sensor or the Crankshaft Position Sensor could be bad. You might also look through the walk through diagnostic I am going to give you. It really goes into more depth than I can here and is a good tool to figure out this particualr situation.

Follow this link;

https://www.2carpros.com/articles/engine-backfires-while-running