losing fuel pressure
Thread Starter
Teching In
Joined: Jan 2020
Posts: 10
Likes: 0
losing fuel pressure just to start things off I have a gen 3 5.3 with fuel pressure regulator on the return and I have an inline fuel pump. the issue I'm having is when the car is under load it starts to lose fuel pressure it'll go from 55psi to 15psi when under load, I'm not talking about just going full throttle, even when I give a little gas to speed up the fuel pressure drops instantly. when I left off the pressure will shoot back up instantly. I've checked voltage to the pump and its fine, I want to say its fuel pressure regulator, but the regulator isn't leaking into the vacuum line as I was told it was a way to check if it's bad and when I pull off the vacuum line, pressure does go up so that's telling me that it is working. idk if I should replace the regulator to see if that's it or can it be a line that's collapsed somehow, or could it be just the fuel pump going bad and it can't keep up.
TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
The regulator is easy to change so i would start with that. What kind of fuel lines do you have? When you say inline pump is that external? If so what kind of line do you have in the tank? Could also be the fuel pump is giving out.
