I have a turbo b18b. I'm running one slim 10" fan. At idle after a few pulls my car will rapidly over heat. If I give it 2k of throttle it will cool back down. This only started after i blew a coolant line one day and over heated without coolant.

Could it be my headgasket?

 

your battery

replace ur battery i had this same problem

see the thing is when the motor is at idle the alternator is not spinig very fast so it doesnt help much to the battery and then if ur battery is old u will have problems like this , it would happen to all system that require power from the battery like the light will dime and ur ac fan will dime when u rev up ur engine

 

How bad did you overheat? you very well could have warped the head/popped the HG.