So yesterday my had problems running and checked the fuel pressure and at first goes to 55 and quickly goes down to 40 psi and trying to know why filter and regulator are changed already by the way

 

Did you change the fuel pump?

 

no I have not

 

55 PSI tops is lower than the 60 PSI you really need. Dropping to 40 PSI is way too low for the fuel injection system to operate properly. I believe that you will need to put a new fuel pump in your Chevy.

I wish I had better news for you, but fuel pumps do go bad over time, and there is no quick fix. At least you have a pickup, so that makes it much easier to do than a car.

 

thanks is what I supected I got the part already have a great night