Weird over heating issue (need help ASAP)

[burninskulls0911]

Here is a little overview of the car and what's going on,
I just put a new 1.6 motor in my 91 Miata, I put new headstuds and a new headgasket on before the motor swap..
It's got a new water pump, cx racing radiator, new cap, new thermostat..

So I put the motor in and on the first test drive I see that it starts to heat up, it only heats up above 30 mph.. (it goes between 3/4 and H)
There's nothing different, nothing blocking the radiator, and I let it sit there and idle for about 30 minutes and it was below half on the gauge which is what it has always been at always..

Now the weird part.. I'm getting no pressure at all in the system, after running and driving there is no pressure on the upper or lower hose, so i changed the cap and the thermostat, no difference.
I can pull the cap off and the coolant is full but no pressure, I'm not losing any coolant, it's not milky nor is the oil.
I'm really stumped on this one and I need my car to get to class tonight.

There no bubbles coming out of the exhaust from combustion leakage, there's no smoke nothing...

Does anyone have any ideas? I'm open to anything

Thanks
Adam

[sidelight]

Put the thermostat in water, and boil the water. Observe at what temp Fareinheit,
it starts to open. Also what temp thermostat is fully open.

stat doesn't even open a little at 200 F,; or not at all then that
thermstat is non-working

[c72c]

Thermostat could be bad- stuck open keepin you from building pressure.
did you burp the system after you got everything back together? you could also have an air pocket in the system, and without enough pressure to push it through, that could be another reason for getting hot.