some advice?

[79rex]

I have a 79 Rx7 that I purchased for $250 back in June of 2002. The engine and transmission had both been rebuilt before I bought it, the previous owner said that they only had 5,000 miles on them when I bought it. I drove the car on a regular basis for about a year and a half and it ran perfectly. Then everytime I would run the car, after about 5 minutes the enging would overheat, and the coolant overflow container would always be bubbling over with coolant. Also, everytime I have the car at idle, it just dies, but it starts right back up when I turn the key. I also keep the negative battery cable disconnected when Im not driving because if I let it sit for about a day, the battery is completely dead. I have no clue what is causing that and the overheating (no leaks are present). I took very good car of the car and did oil changes every three months. Now I only drive the car sporadically because of all the problems, and now everytime I try to start it, I have to adjust the negative cable about 5 times to get the engine cranking. Can someone help me, please.

[1GFDRIFTER]

how much did it cost to have it all rebuilt? i also have a 79 but i want to put a 13b in it down the road. is your motor carborated or fuel injection.