So this morning I went to start up my truck to leave and it start up fine, i pulled up alittle then reversed alittle and when I did that it started to make a loud knocking noise like a banging, then it started to shake excessively. It was running find yesterday. Before this it would make noise nut not as loud and would start up, die, start up, die then finally stay started. Its a manual and has no fuel injection. I have no idea what it could be someone please help.