So I put a black top sr 90-94 into my s13 which is a 90 model and I have spark and fuel all wiring and grounds are good. It just isn't starting it just spins and it doesn't even try to start. Any help or advice would be great thanks.

How are your coilpacks?

Brand new everything

The ecu that I have is a e5 and it came with my 90-94 blacktop sr

Was the wiring harness messed with at all?
Also, have you messed with the CAS during the swap?

I bought a new harness from wiring specialties and no I'd didn't mess with it

Make sure you have fuel and that you can verify you have spark.

If you haven't messed with the CAS, I would consider resetting the timing on it anyways. Someone might have pulled it at some point and just slapped it back in and you would never be the wiser.

Ok that might me it cuz all it's doing is spinning over its not even trying to start

How would I go about setting the timing on it

Set the motor to TDC of the compression stroke (the cam lobes will be pointing up) and pull the CAS. There will be two punch marks on the impellor shaft and a hash mark on the base. You meed to line up the furthest mark and when you go to put the CAS back in, it should rotate the shaft so the mark lines up withe closer punch mark. I might have that backwards, but you'll see which way it spins and be able to get it lined. If that gets you started, you'll still need to double check your timing with a timing light.