Fuel Delivery Problem

[70challengersix]

I am having problems getting fuel to my carburetors (440 six pack challenger).  The attached pic shows my setup.  The fuel is getting to the vapor separator but is not coming out the top to the line that feeds the carbs  The way I have it installed is that the rigid line from the pump goes to the center of the bottom of the separator.  The hose coming in to the pump is the feed line coming from the tank.  The other hose exiting the r/h side of the separator connects to the fuel ventline that parallels the main fuel line back to the tank. 

I disconnected the rigid line (output side) of the fuel pump, and cranked the engine and verified fuel was coming out. 

Is this setup ok, and any ideas on where my problem could be?

[Chryco Psycho]

so you are pushing fuel back to the tank through the return , have you disconnected the line at the carb to see if fuel is coming out there ? the needle could be stuck closed at the carbs . The Vapor separator has in & out stamped on it as well , it is connected properly I assume , possibly the fuel pump is not moving enough fuel to fill the separator & send fuel up to the carbs

[70challengersix]

Chryco, Yes I loosend the lines up by the carb and cranked the engine, and no fuel.  It's not getting out of the separator.  The top port is out to the carbs on the separator, I will check the two lines on the bottom of the separator tomorrow to ensure they are connected properly, but I think they are right. The oulet of the pump is pumping as I had the entire line disconnected (at the pump) and it was squirting fuel.  This separator looks so simple, I cant understand what could be happening.  It must be pumping back though the vent into the tank.   

[tman]

Sounds right by Chryco.  I would find a way to bypass the separator straight to carb for testing purpose.  Is output by fuel pump adequate as far as volume and psi?  Looks like you connected the lines into the separator correctly (according the service manual). Pump to center of separator, the right or side outlet is back to tank, and the top outlet is to carbs.  Have you used this separator before? or is it new?  There is a filter screen inside the separator and that could be clogged or it was made incorrectly.   

[GranCuda1970]

 

[Chryco Psycho]

I would try plugging the return port off the separator & see if ti will push fuel through the separator that way

[70challengersix]

Thanks guys,


The seperator and pump are new.  I will clamp off the return line and see if it get fuel to go through.  If not, I will bypass the seperator altogether and go straight from the pump to the carbs. If that works, that would point to a problem with the separator. 

[70challengersix]

Chryco, I clamped off the return line coming out of the separator and now I get flow to the carbs.  Now I am wondering if there is a problem with the separator, or maybe it just needed primed somehow (althought thats hard to imagine). Everything on this car is new, so, I dont have any history on how it worked before.  Seems like I have hit every stumbling block in this build.  I think that after I get it running, I will unclamp this line to see if I get flow, if not, the saepartor will need to come off

Thanks

[Chryco Psycho]

Welcome 

[73EStroker]

Also looks like your fuel line is a little squashed on the bend coming out of the pump. Restricts a little once you are running at high speed hot day wide open. You know the feeling.

[70challengersix]

Ok, heres what I learned.  There is supposed to be a 0.060 inch orifice in the return nozzle coming out of the bottom of the separator.  If this is not there, the fuel will bypass through the can and not port to the carbs.  Has anyone had a problem with getting a separator manufactured without this orifice restriction?  It should be right on the end within reach of a paperclip.