I have a 2007 Chevy Silverado Classic with a 4.3 liter and it has a single fuel line run to the intake manifold. Im guessing its somehow a returnless system. Im in the process of cleaning up a manifold and wanting to install it since it has external injectors instead of the internal Spider Injectors but the new manifold Im replacing it with has a return line. What could I do about this problem? Would I just drill and tap the tank and run a line? What would you suggest? I know there is 3 lines running from the tank but no blocked ports for a 4th line. Im guessing one is the Evap line and I havent traced the last line yet. If I could get older model tank maybe the extra line could be run to it. Maybe replacing the tank pump with one that has 4 lines off of it would work. Suggestions are welcome as Im thinking about doing the swap around December and then getting Nelson Performance to retune it.
This is one option Im thinking about taking but please let me know if you think it will cause problems or might mess something up. Im thinking about deleting my EVAP and using the EVAP line that connects to the tank to run my return line. Im not going to use the existing line but replace it for the return. Im probably going to purchase HP Tuner Software and Im told that you can turn off all EVAP codes so they dont turn on the check engine light. Im also going to remove the EVAP black box located in the rear of the truck or plug it in case I need it in the future. This will allow me to run a return without messing with the tank and drilling bungs and adapters for a return. This will also keep the stock internal regulator and fuel pump. There is a regulator on the marine intake that Im swapping with the stock to control the fuel line pressure and I wont have to worry about the sensors in the tank sending mixed signals to the ECM and possibly not firing the injectors. Ive included a pic of the marine intake Im installing in place of the stock.
Just a few shots of the single fuel line/returnless/deadhead type system.