New here hope I'm in the right spot. I have a 1997 Dakota 5.2 It was dying out like a flat spot and backfiring through tb I replaced tps and seemed to work ok for a bit problem really never went away. A buddy did a engine swap and had a extra tb off a running 5.2 I replaced and it got to the point wouldn't even start I went and put new plugs in and it barked right off all seemed ok till I got 5 miles down the road and it started same thing flat spot and backfiring through tb any suggestions welcomed. Thank you