fuel return line help

[ukcats07]

I need help with where to connect my fuel return line.  My Z had the motor out 8 years ago and I did not have a chance to mark any of the lines before I put my 5.0 in.  

 

The feed was easy, but I'm afraid I've hooked the return line to the wrong hard line.  As it sits right now, my evap tank is being filled any time the pump is on.  I'm assuming this means my return line is connected to the fuel vent line?  The only reason I find this odd is that line is the second biggest line (aside from the feed line) in the car.  The other line is very small (< 1/4") so I thought it could not be the return line.  

 

Here's a pic with how it is setup now.  Red is my feed line, green is what I thought was the vent line (with vacuum cap on), and yellow is where I have my return line plumbed.  

 

 

 

[88dangerdan]

coming out of the tunnel the top one is the vent, middle one is return and bottom line is supply ( early 260z ) hope it helps

[ukcats07]

So does your fuel return line send gas into the expansion tank? I can hear gas flowing into mine and it has only started this after I connected that line. I thought that expansion tank was only for fuel vapor?

[NewZed]

Your original guesses were correct.  Liquid should not be returned to the reservoir.  You have the wrong line connected.  There is a specific port for returning fuel to the tank.  Labeled drawings are in every FSM, in the Fuel and Exhaust chapters.  Look at the pictures and you'll probably be able to figure it out.

[ukcats07]

Your original guesses were correct.  Liquid should not be returned to the reservoir.  You have the wrong line connected.  There is a specific port for returning fuel to the tank.  Labeled drawings are in every FSM, in the Fuel and Exhaust chapters.  Look at the pictures and you'll probably be able to figure it out.

Thank you, my nose especially was telling me something wasn't right.  Don't take this the wrong way, but can you please tell me which page (and which FSM) shows the fuel line pics for a 73'?  I've checked the FSM, FSM supplement, fuel system modification guide and Haynes (not to mention tons of google searches)--none of which describe in any detail the complete fuel system for a 73'.  

[NewZed]

The process of elimination should work for you.  There's only two left, right, and one of those is supply.

 

Or you can go back the the tank and blow air through the lines connected to the ports shown in the Fuel and Exhaust (FE) chapter (not the Engine Fuel System chapter).  Always good to confirm anyway.  But it looks like the 1973 internet resources don't have that chapter. Could be why you missed it.  So 1972 or 1974 will have to do.

 

Here's a good resource for those- http://www.nicoclub.com/datsun-service-manuals

[ukcats07]

Thanks a bunch.  I should have realized that the 73 is in a weird situation being almost a 260 and all.  I'll admit I've never actually looked at the 72 or 74 manuals.  

 

The whole process of elimination is a pretty easy kill, I just wanted to make sure that the expansion tank was not supposed to have fuel running through it.  I'll connect to the smaller line and hopefully all will be good.

 

Thanks again.