Suspicious sporadic start

[Coleman El]

Hello guys. I'm new here and this is my first post. I just bought a 2003 4.6is. And it needed a little work, according to the seller. He stated that all it needs is a throttle body and maf sensor. I scanned the vehicle with my INSTA software, and sure nuff, it came back with the codes for the throttle and maf sensor and also the pedal potentiometer. I changed the tb and sensor but couldn't get it to start. Mind you, last week, it was the samething. I tried starting it bit it wouldn't start. Went out a few days later, it started right up. Along with the bad idle he told me about. I let it idle for a while to see if it would clear up but it didn't. Turned it off and I couldn't start it again. Fast forward to now, this is where I'm at. Cranks but no start with the TB and sensor newly installed. I checked for fuel in the rails, has fuel. Checked for spark. No spark
I don't know why it would start one time and not the next. Is it possible that it being immobilized? I don't know at this point. Can I get some of yous to help? I would really appreciate it. Thanks. And I have videos of it idling and pictures of the codes I pulled if that would help ya.