Air in fuel line?

[dsd1983]

I have my 455 big block in my '79 Cutlass. Installed new tank and electric fuel pump. I have a clear fuel filter that is new also.

When I go to start my car it struggles to get gas. When I turn the key on the fuel pump kicks on without issue and the clear filter does have fuel in it. But I will try and try to start the engine and it will not start because it is not getting fuel. I can pump the carb and do get a nice spray from the accelerator pump. I have had this engine running on test stand to break in new cam. Last weekend I had the same issue and took the fuel line off the filter and there was like a rush of air coming out of it. Did it twice and then the car started.

This electric fuel pump doesnt need a return line. So I only have the 3/8 line coming out of the sending unit. The return line on the sending unit is not hooked up to anything.
I do have fire to plugs, timing is close enough to start and i do have compression on all cylinders. When I hit the throttle a couple times so it sprays some gas in and it will try to start but it wont because the fuel is not getting to the carb.

Any one wanna weigh in on this?

 

[tetomas]

If you can pump the accelerator and see fuel spray in the carb then there is fuel in the bowl. What are you doing for a choke? 455 cubes is alot of engine, takes alot of fuel to get it started when it is cold. What kind of fuel pressure do you have? What kind of carb are you using? Is the sending unit deep enough in the tank to keep it from catching air? Is the pump in the tank or in the line? If it is in the line could it be sucking air in the suction line? More info would help, and maybe get more ideas from other members.

 

[dsd1983]

If you can pump the accelerator and see fuel spray in the carb then there is fuel in the bowl. What are you doing for a choke? 455 cubes is alot of engine, takes alot of fuel to get it started when it is cold. What kind of fuel pressure do you have? What kind of carb are you using? Is the sending unit deep enough in the tank to keep it from catching air? Is the pump in the tank or in the line? If it is in the line could it be sucking air in the suction line? More info would help, and maybe get more ideas from other members.

Carb is a 650 Holley Double Pump Mech Secondaries
Carb is choked off to where about 5/16 of space is left. If I open the choke all the way it will get too lean and not even try to start. I guess I could richen the idle mixture screw by backing them out
Not sure about fuel pressure, but if i take the fuel line off the carb and have a buddy turn the fuel pump on with the key gas comes out like a water hose running sprays out like there is air in the line for like a second and then a rush of fuel from the pump.
I guess the sending unit is deep enough, it is the one that matches the tank that I got from goodmark. There is 5 gallons in the tank so I know it is not starving.
The pump is an external fuel pump.

 

[rustyroger]

Try disconnecting each fuel line union from the filter to the carb and see if any don't give you a rush of air. Seems to me you have a partial blockage somewhere in the fuel delivery system that isn't allowing enough gas up to the carb.
As has been said a 455 will want plenty of gas, a kinked or obstructed fuel line could be enough to starve the engine of gas. Have you tried leaving the pump running for a while without cranking to see if the carb gets enough to fill the float chamber properly?.

Roger.

 

[dsd1983]

Try disconnecting each fuel line union from the filter to the carb and see if any don't give you a rush of air.

I tried that and when I took the line off of the exit side of the fuel filter it let out air. I took the line with the fuel filter still attached to it and had my wife turn the key on and fuel sprayed out of the fuel line like it is supposed to. I sprayed it into a bucket so it didnt make a mess. So like I said, take the line off the filter and it lets out air. I have someone turn on the key and it pumps fuel fine. As I stated before, there seems to be plenty of gas in the carb because the carb will shoot a perfect stream of gas in the carb both front and back when you push the throttle to WOT.....

Thanks for the insight!

Doug