Problems with starting my RB25 in an s13

[matttt]

I need some help here fellas. I got my engine swap done at Top Hat Performance in Conyers, Ga. I got the car back and it was running fine, but I drove it around for a couple of hours and it just shut off on me. I couldnt get it to start back up at all. I had an SR20 radiator in it but that wasnt workin out so I got a new one for the KA. The weird thing is that the engine will not start if there is a good flow of coolant running through the engine. I disconnected all the hoses and plugged up the hole in the engine where the radiator hose comes out of, and the car cranked right up, and when i took my hand away, it shut off. So i hooked everything back up and the car will only start when the radiator hose(the upper one) is completely kinked and there is no flow getting through the radiator. If anyone has any idea whats wrong, let me know! Its been almost 6 months since ive had my car!