Couple years ago we purchased the car and about a week into owning it the engine began to knock so we dropped the 3800 and purchased a rebuilt 3800 and installed it into the car and ever since it'll attempt to crack but won't fire. Not sure what the problem is we've replaced the starter as well and no luck, looking for some more opinions on what to do on how to possibly fix it. It might be the crank sensor but we're not sure.