My burb has been down since Thanksgiving, this is what happened I went to go to work on a Monday and it sat all weekend and when I tried to start it it slowly turned over kinda like the battery may have been almost dead I tried 3 time and got nothing, so I decided to take our other vehicle and mess with it when I got home, so I got home and tried to start it and got the same result, tge first time and on the second time I heard a pop noise and smoke coming from under the hood, popped the hood and it backfired through the intake and blew it to peices, so I bought a new intake manifold replaced it and nothing my uncle said it was the crank sensor and same result, so since then I have replaced, fuel pump and filter, injectors, map sensor, crank sensor twice, distributor, plugs, tested the wiring for the injectors, plug wires, and what not, so this is what I have now, strong spark on cylinders 1,7,2,8 and I have a weak spark on 3,5,4,6 any help would be greatly appreciated thanks!