Yes, it is important to keep. The only time it is absolutely necessary though is during pump prime or in the event that the FPCM fails and gives the pump full voltage. My setup was similar to yours; I just had dual stock pumps. Kept the returnless, kept the pressure relief. My goal was not dealing with the check engine light...worked fine

 

Ok, I see your thread and the picture you had, posting it below hope that's ok.

Do you think the Walbro pump just sitting in the bucket would be ok? I guess I could test that with fuel in a 5gal bucket. I would just need to find a filter to use.

 

That thing was way too ugly to post again It looks like crap and was a pain in the *** to get into the tank...but it worked well. I wanted to use the stock fuel lines so I had to put the filter in the tank.

What do you mean 'just sitting in the bucket'? Like unsecured, or..?

 

Just seemed like the stock pump was helping fill the bucket, I'm probably over thinking it. I will secure the 450 in the stock bucket, likely cut the stock filter leaving more volume in the bucket, put an inline filter and the pressure valve intank as well, much cleaner that way and will test it before putting it in.

 

**Quick Update**

Since it's not that simple to get the Walbro 450 in there on these NNBS' I decided to order a Flex-Fuel pump and got that installed, was able to raise the boost to 12psi with no more issues now

 

I did a quick setup with the walbro 450 hook straight up to the feed line. Turn key on 58lb start up engine comes down to 42lb like the flex pump did. I rev the engine stay on 42lb. I know there is not load on the engine so I think this is doing ok. I cant remember how the stock flex pump work reving the engine, I will tune engine to run better before testing more. I also need something to fill up the bucket. Im thinking about a small hole in the feed line. Any ideal ????

 

DO NOT put a hole in the feed line! The regulator is in the bucket next to the pump, which means the excess fuel will fill it up very quickly. A couple primes and I bet its full.

 

Atomic, there no reg in this bucket, only a filter and looks to be a orifice to fill up buckle.
I ran the truck for a hour bucket only the height of the fuel in the tank. You can
the see the orifice in the pic GXPJAY posted.

 

Yeah from what I see there's only the filter and the over pressure valve, which keeps opening at idle now that I put the Flex Fuel pump in my truck.

 

I check my valve or what every it is called. It not a check valve or pressure valve because I can blow threw it both sides. Check your.