I bought a '79 924 that hasn't run for several years. I rinsed out the fuel tank put some new fuel in and changed both fuel filters. The car started and barely ran with the fuel pump buzzing loudly with the tone varying wildly (like the pump was loading up and not pumping) and the car would eventually just stall out.
I figured the pump was on it's way out so I ordered a new one off of ebay. I installed the pump and the car now stays running and will even rev up but the tone in the buzzing still varies (if slightly quieter) and the idle fluctuates as the buzzing varies in tone.
I've only put about 4 gallons of fuel in because I'm still sorting out all the leaks.
I know the fuel accumulators aren't holding pressure because fuel is weeping out from around the little screw in the bottom of them (indicating the seal is defective) but I didn't think they served much of a function except for hot restarts.
Did I buy a defective pump or is something else at work here?