So I bought a 91 LX 5.0 a couple months back. Did regular tune up and cleaning.. Had troubles but most of them got fixed. I am now having trouble with what I believe to either be the TFI module or my msd ignition box. There is currently a Wells tfi on now. When I first noticed a problem was trying to start the car after it was warmed up. I would try try try but it wouldn't turn over. I sit sit sit and get a jump and starts right up, assuming I killed the battery and the TFI cooled off. So I replaced the TFI (with one from LMR) and drive around and car cuts off in middle of the road (pretty embarrassing). Push into a gas station and let sit, and a buddy tells me to hook up stock ignition. Starts right up with no jump. I ordered a "Motorcraft" tfi from rockauto. Same problem except I was able to put the original tfi on right away and stock ignition and fired right up. I'm lost at what to do. Thanks for any help everyone.