1988 Nissan Pick-up 2 wheel AT

Ive' been working on a (1988 nissan PU/2W/AT/Z24) I just swapped engines and at first the truck started right up but ran a little ruff, I noticed that when installing the intake manifold, I put the gasket in backwards, because collent was leaking, so I fixed the mistake. But when I was done rapping it all up. I tried to start the truck again. It would turn over but not start. Then I put gas in the jets and it would start up. Of course when the gas was gone it stalled, and wouldnt start again, it will turn over but not start. I did check the vacuum-lines and electrical plugins, and nothing is happening. What do I do?