1997 Nissan Altima, Stalling

Hi all,

I have a problem with my nissan altima 1997 model car. It stalls on me. I thought it might be the fuel filter, changed it, with no help. Then changed the fuel pump, distributor cap with rotor. This helped me, I thought, because the car cranked and ran for 1 week. Now again, its coming down, the RPM wont stay for long, it will come down to very low rpm's of about 300-400 and then stall on me or in other words the engine will go off. My mechanic was telling me that there is some sort of an electrical connection near the fuel tank, which he saw was getting damaged due to the heat and I may have to change it. Also, he doesn't know what the part is and he says it might cost real high. So I was wondering if some one could help me out of this problem. I have spent almost 200$ for changing the fule pump, fuel filter, rotor, spark plugs, distribution cap etc. Please help me fix this problem. Thanks a lot