Engine will not turnover is the starter bad?

Engine Mechanical problem
1994 Honda Civic 4 cyl Two Wheel Drive Automatic

i replaced the heads with a vtec heads and I hooked everything back up. When I turn the key I could hear a clicking sound but the engine wont turn over. All the lights work and everything. I could also hear like a pressure sound. I think its the fuel not sure though. I know I have to replace the ecu so that vtec will work but I was told it should still run with the old ecu. What could possibly be wrong. I am hoping it is just a plug I left disconnected but I cant find one anywhere. The engine does not even try to turn over. Any idea?

It is a d15b7 engine and I put a d15b vtec head on it.

It does not even attempt to turn over just clicks

Ok so I got it to try to turn over it was a connecter I left off. Now I am trying to figure out how to adjust the timing belt. The timing belt I have on it is really loose. Is there a different timing belt I will need to put on it since I changed the heads?

Replaced relay, car will not start in 32 degree weather but does today on a colder day, turn over, so it is not the starter? Have intermittent problem for 2 weeks, it sometimes starts and sometimes does not