5.3 GMC

At idle my fuel pressure is 44 and only 52 at wot. Walbro 255 in tank is brand new. What can I do to get it back where I need it?

53bowtie

iTrader: (6)

Have you changed the fuel filter in a while?? Also might run some cleaner though in the next tank of gas.

5.3 GMC

It's gettin changed tomorrow although it doesn't have more than 10k miles on the one in it now.

rmck490

If that's not it, maybe the fuel pressure relief valve.

5.3 GMC

Where is the fuel pressure relief valve located?

rmck490

I meant the fuel pressure regulator actually. I hope that didn't confuse you. It would be on the fuel rail on the driver's side of the motor.

5.3 GMC

Well I changed the fuel filter today and it's still the same. I guess a regulator is next

53bowtie

iTrader: (6)

If you have a gauge to put on the fuel rail you can disconnect the vacuume hose on the top of the fuel pressure regulator and the pressure should go up to 70 ish. Then you know it is the regulator that it bringing it down to the level its at. Also, the regulator could be leaking if the vacuume hose is wet although this normally will make it flood a little not drop pressure.

5.3 GMC

Swapped out the regulator and got it back up. 52 at idle and 58-60 at wot