LCTom

I have a 1997 2 Door Tahoe LS 5.6 V8. recently I've had trouble the fuel pump running about 10 to 20 seconds after off the ignition. It seems to be worse in the morning and in cold weather. I installed a brand-new fuel pump, fuel pump relay, fuel lines, fuel filter, oil pressure sending unit and I'm still having an issue with the pump running after the ignition is turned off. I'm stumped..... any help would be appreciated.