Can Fuel Bypass the IP via Fuel Filter Assembly

[turboman1]

Couple Questions.

- Can fuel bypass the fuel filter assembly? Meaning the fuel goes through the lift pump and past the seals in the filter assembly and back to the tank without ever making it to the IP?

- Anybody with an electric pump in series with the lift pump still have their fuel press guage pulse back and forth?

I ask because i took the fuel filter assembly off to get to the back of the head to put a water temp guage in, and when I put it all back together and started the truck the fuel press guage was barely/nonexistent pulsing. This is odd because it usually pulses about the same all the time except for high rpm and after the fuel gets hot.

Thanks
Adam M.

 

[White Knight]

In a 12 valve? No, the return lines are totally separate from the feed line (except the injector return which just loops back into the feed so there is no loss there)

Can't help on the second one.

Do you mean the gauge reads but doesn't pulse?

 

[BgBlDodge]

Most likely you got air in the line to the gauge and the air is acting like a shock absorber.

 

[turboman1]

The gauge reads and pulses at the same time so it is hard to tell what the fuel pressure acutally is.

So you think i should just try and bleed line to get possible air out of it?

Thanks
Adam M.