overheating......

[talonite]

yes its still stock motor. and i just did the headgasket at my work, looked fine before, and now its new and still doin it. But my fans dont kick on by them selves when the engine is hot and it wont do it if i leave them on. But if i let my car idle for a while then give it a little gas and let it sit again with no fan (cause it wont kick in) it boils over, i mean i have all new components cooling system wise and i put my stock fan back in. And everything mechanical and sensors checks out, so im wondering if it could somehow be related to tuning or an issue with the eprom ecu i put in.