2004 1500 fuel lines. If return-less, why 2 lines?

[Rattlewagon]

I'm sorry for the silly sounding title but, I am looking for knowledge.

 

I'm working on a 2004 Silverado (not mine) with rusty brake lines. I was told by the guy who owns it, the dealer told him a while ago the fuel system was return-less. I've never clapped eyes on a return-less system so I was surprised to see 2 lines going to the fuel rail.

 

One is steel, the other black plastic which appears to be connected at the top of the engine next to the Schrader valve with a green cap to check fuel pressure. All of which is under the plastic engine cover that says "Vortec".

 

If its return-less why 2 lines?

 

sorry, and thanks everyone!

dan

[carnau]

That black plastic hose running to the top of the engine is the purge pipe for the evap system. Connects to the purge valve. The green cap is where you introduce smoke or pressure into the system for checking for leaks in the system.

[Rattlewagon]

Thank you. When I removed the coupler for that line at the back of the engine, fuel poured out of it? All things being equal, would it be expected for that line to be dry? Or, at the least, not have have a half a gallon of fuel come out before I could the lines back together?

 

I feel silly asking these questions like this, I've never had reason to work on something this new..

[KARNUT]

News to me, I thought after the carb days and low fuel pressure, fuel injection came with high pressure and a return to the tank.