I have been having fuel pump issues recently, that being, my car starts fine the first time every day. I listen for the 3-second fuel pump whirr, start the car, and I can drive around as long as needed. however, once I turn off the car and put the key in the number 2 position, I listen and the fuel pump only runs for about a second. then when I start the car, it dies after idling for about a second and there is no fuel pressure.(checked the schrader valve on the fuel rail). Any time I try to start the car after that, the fuel pump doesn't go on at all, it just cranks and cranks. my battery is good, I have a brand-new pump relay in there too. somebody help! also, I tested the power going to the pump, and it lines up with what I previously mentioned. so I believe the pump itself is fine. what could be causing this mess?

 

try measuring the voltage at the relay when you expect the pressure to drop then measure the current draw of the pump. usually when pumps start to fail they start drawing too much current and the pump over heats.