I just hooked up a fuel pressure gauge to my fuel rail. With the ignition on pressure read 50psi. With the truck warm and at idle it read 49psi. I always see we should have 58psi. My truck is a 2003 RCSB 5.3 stock fuel pump 90,000 miles. When I get the walbro 255lph will these pressure numbers change?

 

yes and i wouldnt be doin much racing the way it is now

 

So the pump is bad? Will the filter cause that also?

 

check your filter and see if you can blow through it..if you cant change it..dunno if that could cause it..also with the motor running pull the vacuum line off the regulator and see if there is any fuel in it..if so the reg is bad..but if good your pump is dwindling

 

Thanks will check it out trying to get my numbers correct before the new injectors go in. Thanks

 

Well pulled the vacume line off the regulator while at idle and no sign of fuel. Ill just go ahead and order new pump and get it over with.

 

What is your FP with the vac line removed from the FPR? Did you check it with the vac line attached or removed?

 

50 psi is acceptable for a flex fuel engine...is yours FF?

 

I think your pressures are normal. MIne is also 50 at idle but what counts is pressure at WOT. MIne reads 58 at WOT.

 

mine is roughly 55-58 at idle.