i am new to the forum, and im wondering if anybody knows how to fix my problem. i have an 03 1500 that my brother rolled, after he rolled it he said it started but ran like crap. he found an 02 with a bad engine so we swapped the motors out and now it wont start, it will crank over and try to start but then it back fires through the intake and killes it, it only hits once or twice before it back fires. i have checked the timing and everything is sitting where it is supposed to be, and i have changed the cps (cam position sensor) and still nothing. thanks!