Classic/Antique Car Repair: Fuel Tank Cleaning/Sealing, vacuum leaks, pontiac sunbird

Question
Hi Mr. Sears:
I'll think I should replace the fuel pump on my 88 Pontiac Sunbird w/2.0L OHC engine (140K miles).  I've been getting a fluctuating fuel pump pressure between 9-13 psi, hesitation and no power.  The engine doesn't accelerate when goosed.  The block learn is 145 and doesn't change at 2500 rpm or idle.  There aren't any vacuum leaks.  I've voltage dropped the circuit, etc.  Every thing points to the pump, except the volume is 2 quarts/minute.
   Have you encountered fluctuating pressure?  My main question-- the tank may be full of rust/slime, etc.  I'd like to clean and seal the tank, but this process seems more difficult that the pump replacement.  What is a good way to clean/seal the tank?
    Thanks for your help and wisdom.
Regards,
Barry London


Answer
Ok, a question for you. When doing the volume test where are you breaking the line to test volume? It does sound at this time that the fuel pump could suspect. I would also check the pressure regulator that is mounted in the throttle body. It is also possible that there could be some deterioration in one of the flexible fuel lines. Let me know where you are taking the volume test.
Brad