Hi all. I know that on some this are on the fuel rail, but it is not there. I have followed the fuel lines all the way back to evac tank and then to the fuel tank. But no sign of filter or pressure regulator, is it all on top of tank? :-) Thanks for answers.

 

 

On our generation GM LS engines the fuel pressure regulator is on the fuel rail by the intake manifold. It is on the driver side fuel rail above the coil packs about midway and has a vacuum line to it and a metal clip around the edge that holds it the rail. I've circled it on mine below.

 

i think 03 it the only year to have external regulator and filter.

 

2003 only..

 

My bad - I know the 2003 was the only one with an external fuel filter but I was not aware that they also removed the FPR from the fuel rail on later years. Seems like they made they far more of a pain to replace.

 

FPM comparison:

 

how does that catch can work for you mixman? does it trap a lot of oil? been thinking of adding one but my throttle body does not get excessively caked so have not bothered yet to get one.

 

In 10,000 miles, maybe a couple of tablespoons. My 99 GMC with the iron block 5.3 (essentially the same engine) gets about twice as much. Not sure why but my guess is the 03 valve covers probably have a better splash shield in them under the PCV.

 

Just to be clear, you only have 1 fuel line(supply) +evap line(burn vapors) Returnless fuel systems since 2004. Returnless EFI systems typically operate at a higher pressure than return-type systems. This is necessary to reduce the risk of fuel boiling and vapor lock in the injector supply rail during hot weather (since there is no recirculation of fuel from the engine back to the tank to keep the fuel supply rail cool). The FPR is mounted on the pump found in the FPM.