Ok to start off I just put my new motor in like three weeks ago got ruffly 350 miles on it and for whatever reason its starting to do this.... will run fine for 20 min driving the all of a sudden I cant give it any gas cause it starts back firing spitting at me.... does that then after I get off shift 12 hrs later runs like a bat out of hell... then get in it ruffly 6 hrs later and now I can't give it any gas when in gear or it spitts and back fires I have done ground checks and updates with bigger wires in some places I really need help this is my dd and now I am having to share the car with the wife and its not esay when we both need to be somewhere at same time