new rebuild engine good compression ,engine starts , stays on for 5 seconds then it dies ,fuel pressure is good never dies,, what can be the problem ?????

 

Start and stall problems scream vacuum leak. Check the vac lines and the gaskets between TB and UIM as well as the UIM and LIM.

After that check the AFM plug. Actually unplug it look at all the pins and then replug it making sure the fit is snug.