Help: Fuel Setup Stock Tank 280zx

[OldZNewLife]

Hello! First post here, was wondering what everyone used for their fuel setup on their stock tanks.

I have a '79 280zx with a 5.3 (l28 saved for a 280z), stuck on what way to get the ls fuel pump to the stock 280zx pickup tube in the tank. Would there be any safety issue if I use a kit like the one pictured and just clamp send/return from the tank directly to the Corvette style regulator, or would that work just fine? 

 

Any info would be great, thanks! 

Edited February 25, 2020 by OldZNewLife

[Richard Oben]

The stock ZX pump is not likely strong enough or big enough to run the LS.  That being said if the hard lines are big enough swapping to a larger in tank pump should work.  The regulator should be fine as long as everything is rated for the pressure and fuel.  We did it totally differently, on a 240z.  

[OldZNewLife]

Thanks for the reply Richard! Although you have it slightly backwards; Sorry, I should have stated I already have an external fuel pump rated for a LS engine to replace the stock pump (Fuel OUT on the 'vette regulator will have 6AN fittings and braided line to the fuel rail, while fuel IN and RETURN will most likely run the lines you see in the picture with the white fittings).

My issue is, safety in mind, with the lines for fuel IN and RETURN both rated at 150psi or higher, would it be a problem if I just pushed both ends directly onto the existing in-tank pickup tube and clamped them down? Or would I need to modify the pickup tube to accept AN fittings? 

[Richard Oben]

So sucking through the stock pump?  I would swap or make the stock pick up just a pick up.  JMHO. Richard. 

[260DET]

On 2/26/2020 at 5:48 AM, OldZNewLife said:

Thanks for the reply Richard! Although you have it slightly backwards; Sorry, I should have stated I already have an external fuel pump rated for a LS engine to replace the stock pump (Fuel OUT on the 'vette regulator will have 6AN fittings and braided line to the fuel rail, while fuel IN and RETURN will most likely run the lines you see in the picture with the white fittings).

My issue is, safety in mind, with the lines for fuel IN and RETURN both rated at 150psi or higher, would it be a problem if I just pushed both ends directly onto the existing in-tank pickup tube and clamped them down? Or would I need to modify the pickup tube to accept AN fittings? 

 

Check what the regulated fuel pressure should be, around 50 psi rings a bell. AN fittings are good because they are easily disassembled unlike push on fittings so use them at least with something  like a fuel filter.

[walkerbk]

the fuel being sucked up the feed tube will be under vacuum since it is before the fuel pump (you did say external fuel pump right). the return line will be pressurized but that is only due to flow restriction of the line (i.e. the line is the only thing holding the fuel back which creates pressure). The return line shouldnt be more than 10-15psi at idle which is when it will be its highest. 

I say replace those old crusty lines with some new f.i. rated fuel line from the parts store and you should be good (you could keep the current lines too).