stang69

i know there's alot of info about 4th gen tank but i could find anything installing to tpi system. everythin i have seen when converting engine to LS series. i wanna know if it is possible to upgrade to 4th gen tank because my tank has crack filler neck at the base of the fuel tank. And i wanted to switch to 4th gen tank. is it possible?

85IROCzzz

iTrader: (1)

https://www.thirdgen.org/forums/ltx-...k-plastic.html

That's the info on the tank I'm not sure what exactly you would need to make it work for a TPI, probably just an acceptable fuel pump and the correct fuel lines running to it.

stang69

Thanks for info

skibum2100

I am doing exactly the same thing...for exactly the same reason.

You will need to disable the built-in fuel pressure regulator on the sending unit, to allow the pressure regulator at the rail to do its job. Make sure you look the LS1 tank over carefully, pull the sending unit and inspect it before you buy it. I didn't and now I have a rusty pump with water in the tank.

The LS1 pump is more than enough to supply the TPI.

For fuel "pressure" connection: Use a quick connect-to-hose barb( http://www.summitracing.com/parts/RNB-800-170/ ), 3/8 high pressure fuel hose, and a 16mmx1.5 oring fuel line repair kit ( http://www.summitracing.com/parts/RNB-800-121/ ), with proper fuel injection hose clamps. I tried to adapt/alter the factory 4th gen nylon fuel line but got very frustrated, quickly.

For fuel return: Use regular 5/16 fuel hose (low pressure is fine).

If you can use a soldering iron, then wiring isn't a problem.

That just leaves the fuel level sender...change the sender or change the gauge...do a search of these forums and decide which solution is best for you.

Hope this helps.

stang69

thanks skibum thats the answer i was lookin for. i take it that still use evap that is in front of engine or evap box on fuel tank?

skibum2100

Your welcome.

You could easily add a section of 1/4" fuel hose to connect the fuel tank to the fuel vapor metal line (and retain the factory evap), however the evap box that comes with the LS1 tank is superior in design and function. The default position for the LS1 evap box is open (vented through charcoal filter). So (without changing a thing) we will never have a vapor pressure issue inside the tank and we should never again smell gasoline vapors.

Save yourself a few dollars and re-use the factory fuel lines as much as you can. Boil some water and put the factory nylon fuel RETURN line in the hot water. The important part here is to heat up the quick-connector and some of the nylon line (4-5"). Get a razor blade and carefully split the warm nylon hose where it goes over the plastic barb of the quick-connector. Carefully, because these parts are all warm plastic now, they cut real easy.

The method in the attached picture is great (all credit to z28evans). He used the "HELP" brand of quick-connector adapter (available at most auto parts stores) and a compression fitting with hard lines all the way to the engine bay. I would prefer to have a flexible portion near the fuel tank (so body shock never reaches the fuel sending unit) therefore I will be re-using the factory rubber portion of the fuel line.

Hope this helps.