Hello this is my first post! So I have a 2000 Chevy 1500 4.3L with 360k miles and want to keep it going. I don't know much about the maintenence history but from what I can tell the engine and transmission have been replaced or at least rebuilt. My problem started about 3 months ago when I parked it while it was low on gas the next day after putting gas in it it wouldn't start. To make things worse I lost the key. Well after trying to start it with a screwdriver (dumb idea I know) I had to replace the steering column. Got a good deal on one and my steering wheel was torn up anyways. Reprogrammed the security and it started right up. Well next day wouldnt start again my battery tested bad so got a new one but still no start took the starter off and it tested bad so I replaced it. Started right up drove it one time and the next time I went to start it the nose cone of the starter was broke off inside the flywheel. The part store replaced it for me and it started once and I havent got it to start since. I have checked and I have good spark and fuel and the engine turns over like it wants to start but then it sounds like it almost reverse spins and my first thought was its a timing issue because there have been a few backfires since I've been working to get it to start. I don't have any codes to pull because the computer reset when I changed the battery but I have tried with a cheap code reader and got nothing. I can't take it to a mechanic because Im poor but im pretty good at fixing things so why not just do it myself. My question is would the crankshaft position sensor still let spark happen if it went bad?