Help!!!! New to Toyota Nation, Camry Overheating

Hello! I need some help with an overheating problem with my 1992 Camry V6. It is overheating a couple of minuites after startup.
Background: 2 years ago I had replaced the head gasket and machined the heads after overheating it. So I know the expensive experience!!! It ran fine since and then the horror started again --- 2 days ago.

I discovered the top radiator tank had blown. I took it to a radiator shop, had them throughly clean and test the radiatior for leaks and blocks and put a new tank.

However, as soon as I started 3 minuite laters the engine started overheating. The Fan is working and there are no leaks.

Only thing I could tell is that the water/antifreeze was not flowing at all with the radiator cap open and would only accept about a galon of water. Soon after it would start boiling in the plastic resovoir.

What cold be the cause!, Is there some blockage ex. thermostat!!

Please help! This new member will greatly appriciate any assistance.