My fuel pressure has dropped recently. I used to always run around 25 psi at idle and now it's down to 15 and drops with throttle. I lost a trasfer pump 3 years ago (about 12000 miles.). At that time I had the dealer stack a transfer pump and lift pump in tank to help with fuel pressure and figured if one went out, the other would push enough fuel so I don't lose my ip. I replaced filter, so that's not the problem. My question is how do I check to see which pump is bad so that I don't have to have the dealer tear me a new one again.

Thanks for the help

I just lost tranny in my car so I am depending on old reliable til car is fixed

 

there's nothing wrong with your fuel pressure, iv'e been running with a little less for years

 

Pretty easy since they are both electric. Disconnect one and check the pressure. If it is zero the other one is bad.

 

It was the transfer pump. I was told that if the lift pump in tank goes out, there is no way for transfer pump to pull any fuel through. New fass transfer pump installed and now 30 psi.