I've twice refused to fly hired club aircraft with U/S electric fuel pumps. One one occasion, I was told afterwards by an engineer that it'd been like that for a week, that I was only the third person to notice and was the only one not to agree to fly it.
I remember one aircraft where both fuel gauges were permanently stuck on 3/4 full for at least a month. On one preflight just after a student had just landed it I could see no visible fuel whatever in the tanks. Another time the wing bolts on a PA-38 were so loose you could move the wingtip several inches from side to side.
I'd booked an aircraft for a 2hr flight to Europe for a weekend away and it was handed over with an extremely soft tyre and a bad misfire on the left mag. After complaining, I was told there was a slow puncture in the tyre & that the engine had been oiling plugs all week. They offered me a spare set of plugs, a plug spanner & a footpump. I turned around and drove home.
Always check everything before you fly, particularly on something you've just rented.