I have a 93 sc300 that i purchased with the engine out and torn apart. I rebuild the engine and put it back together. It will fire for about 5 seconds on first crank of day. Any time cranking after that it will bust off and try to fire but mainly just spins. It has fuel pressure and spark. Checked timing and injectors.

Could this be a this be a sensor or vacuum?
I did delete EGR and AC, also rerouted some vacuumed lines following a thread and YouTube video.

What else could I try? Any input is appreciated