Interesting info about the fuel system...

[HybridOne]

if you hook your fuel lines to your rail backwards, the stock injectors won't fire. The fuel pressure reads about 60 or 65 psi...and i think thats too much for the stock injectors, or maybe the regulator won't let the gas in backwards....either way....fun information.

[llamabeta]

The regulator wont let fuel in from that direction. This happens alot on SR20DET installations. Remember the return attaches to the regulator.