I started the 91 Q45 last night and heard the humming noise from failing fuel pump. So as heard the noise, I shut it off quickly to keep from damaging the Fuel Pump Control Module. Not bad for 28 years and 165,000 miles.
Actually, I purchased a Nissan replacement pump several years ago to keep on hand for then the original pump decided to fail.
I will change it in a few weeks when the weather warms up a bit. I'm not driving the car right now.