Hi, Team.


I have a 2001 Lesabre that while I was tracking down a starting issue I tested the fuel pressure. On the first turn of the key to the on position (no cranking) the fuel pressure goes to 10 psi and then on the second turn of the key the pressure goes to 46 psi. Why would the first energizing of the pump only produce 10 psi and then jump right to 46 on the second?


Thanks,

Welcome to the forums.
Generally before a rail pressure test, it is recommended to replace the fuel filter first.
Have you replaced the fuel filter?

I agree, do that first....the other possibility is the check valve in the fuel pump....f/p regulator leaking.......doubt an injector, you would have driveability problems......external leak? would smell gas.....

I have not replaced the fuel filter, I'll do that first. There is no gas smell and I did pull the vacuum line off of the regulator and there was not a leak. The system holds pressure, it just doesn't want to give pressure on that first turn of the key. After 4 or 5 times of turning the key twice to get the pressure up, the system would pressurize to 46 on the first turn of the key.