1936 LS1

iTrader: (10)

I'm using an in-tank Walbro pump and the stock '02 Avalanche fuel rails on my 5.3. Do I need the Corvette-style regulator/filter with this setup?

Thanks,
Richard

Agent_Orange_Shuvel

iTrader: (8)

I don't think so, if they are 02 fuel rails they should have a regulator and return line on the intake. Maybe some one with a little more experience can confirm. Or pics would help.

arthropraxis

If your fuel rail only has one inlet you will need the corvette filter/regulator. If the rail has an inlet and outlet then you would not use that kind of filter/regulator.

1936 LS1

iTrader: (10)

Thanks. It has a return line.

1936 LS1

iTrader: (10)

Resurrecting this thread since I'm finally at this stage of the build. I'm gonna keep the rails with the return line, since that's what I've got on hand. I've got 3/8" SS hard line for the feed line from the in-tank pump. Here's the rest of my plan and questions.

Add stock filter for '02 Avalanche (motor source) on frame rail, then continue hard line almost to the motor.

Where hard line ends, what should I use to connect hard line to stock fuel rails?

What do I need to use for a return line?

Is rubber line (FI rated) OK for feed and return?

Thanks,
Richard

arthropraxis

Where the hard line ends to the fuel rail you can use compression fittings with an AN end then connect that to a stainless braided fuel hose, expensive.
A less expensive option is to use fuel injection hose and fuel injection clamps with either end using barbed fittings one with an AN to fit to the compression fitting and the other with a quick release to the fuel rail.
Dorman sells a fuel injection nylon hose with a quick release. It is necessary to heat one end to fit over the fuel hard line. I have not had good luck with those.
Make sure of the feed and return sizes. One is smaller than the other. FI hose is fine for either. The return is not under pressure, you may be fine with regular fuel hose for the return line. Check on that to make sure. FI hose is expensive.

gofastwclass

iTrader: (2)

Rubber FI hose needs to be able to hold at least 60 PSI working (system runs at 58), the stuff I use is good for over 100 and was acquired behind the counter at the local O'Reilliy. The external FI hose isn't very bad, it's under $9 per foot retail. You won't need much, just a bridge between parts that may move or vibrate. Obviously the length will vary with application.

You can also purchase the GM quick release fittings in the "help" section for around $10. The parts store will also sell high pressure fuel injection clamps that are actually less expensive than the typical worm clamps and don't dig into the hose. By the time you are finished, you have a complete fuel system for less money than the braided hose alone would cost, and we haven't even priced fittings! This method is tried, true, super cheap and just as reliable as the braided lines and numbered fittings some people think is the only way to go. ...and did I mention I use it on my daily?

What you use in the tank needs to be submersible or it might not last long. O'Reilly can get that too but it comes in 1 foot sections and they typically don't stock it. Gates makes two sizes, 3/8 and 5/16 and it runs ~ $25 retail.

The part number for the 5/16" submersible (typical return) is Gates 27093 while the 3/8" submersible (typical pressure) is Gates 27097

HTH

1936 LS1

iTrader: (10)

Thx for both responses. They are very helpful.

1936 LS1

iTrader: (10)

A follow up question. As I started ordering my parts today I realized that the tank has the same size fitting on supply and return. Both accept a 3/8" NPT fitting which should correlate to a 5/16" line. Fine for the return but I was planning 3/8" for the supply side.

"OK, so change out the supply side fitting to 3/8", right? But it's attached to the pump and the lines inside the tank aren't 3/8" so, why run 3/8 all the way to the fuel rails if it's restricted at the pump discharge anyway? Walbro 340 in-tank pump, BTW.