Lack of fuel?

[Dat_z240]

Help!

I have a 72 240z and the fuel filter in the engine bay is 1/4 full.. under the filter line and wont fill.

Just installed a new electric fuel pump and filter, new braided fuel line and a new filter before the mechanical pump but the pressure seems low and it's not filling. As the pump turns on you can see bubbles in the filter (in the engine bay).

 

Question is could there be air in the line? Do i need to bleed a fuel line?

Car is hesitating when driving, constantly jerking like its starving for fuel. 

What could be causing this? Anyone experience this before?

Note: Gas tank is half full. Electric fuel pump is 4-7PSI. Got the tank cleaned but not coated (suspect i need to clean it again due to a bit of debris). 

 

Edited August 5, 2020 by Dat_z240
Updated pictures

[SteveJ]

1. Make sure your fuel filter (stock design) is mounted vertically with the outlet on top.
2. Inside the fuel filter, the opening for the outlet is low when the filter is mounted properly, so the fuel does not fill the filter typically. I hope this image give you a good visual.

The photos you posted are in a format that users with Windows computers cannot open easily. I am lazy and do not care to install software that allows me to look at them. You may want to look at converting the photos to a JPG format.

As for fuel starving, go back and give us details. 

1. Why did you add in the electric fuel pump?
2. Do all of the fuel lines have smooth bends that don't kink the hoses?
3. Have you checked the fuel pressure between the pumps? You don't want too much pressure (>4 PSI) on the fuel rail, as you will overwhelm the floats.

[Mark Maras]

 Welcome. I've never heard of anyone having to bleed the air out of a fuel line. My 71 engine bay fuel filter (mechanical pump only) was never full but if you're seeing bubbles being pumped into the filter there's a leak somewhere in the system, probably between the electric pump and the fuel pick-up in the tank. Assuming you replaced the parts to cure the poor performance and your carbs are SUs, have you checked the filters in the banjo fittings on top of the float bowls? The float levels are the primary mixture adjustments. An inexpensive Fram clear plastic fuel filter between the tank and the elec. pump will let you know if there's still debris in the tank.

 

[SteveJ]

Also, where did you mount the electric fuel pump, and what is the orientation? What does the manufacturer's installation instructions say? What brand/model electric pump did you install?

[Dat_z240]

1 hour ago, SteveJ said:

1. Make sure your fuel filter (stock design) is mounted vertically with the outlet on top.
2. Inside the fuel filter, the opening for the outlet is low when the filter is mounted properly, so the fuel does not fill the filter typically. I hope this image give you a good visual.

The photos you posted are in a format that users with Windows computers cannot open easily. I am lazy and do not care to install software that allows me to look at them. You may want to look at converting the photos to a JPG format.

As for fuel starving, go back and give us details. 

1. Why did you add in the electric fuel pump?
2. Do all of the fuel lines have smooth bends that don't kink the hoses?
3. Have you checked the fuel pressure between the pumps? You don't want too much pressure (>4 PSI) on the fuel rail, as you will overwhelm the floats.

*Pictures updated

The filter is in the stock location and mounted straight. 

1. The car had an electric fuel filter when i got it. Assumed it needs it so i left it on and replaced it with a new one.

2. Checked and don't see any kinks in the hose. 

3. I have to get a pressure regulator to check the pressure. From the electric fuel filters its a lot but when i take the hose off by the engine bay it squirts little then stops then squirts and stops on and off.

[Dat_z240]

1 hour ago, Mark Maras said:

 Welcome. I've never heard of anyone having to bleed the air out of a fuel line. My 71 engine bay fuel filter (mechanical pump only) was never full but if you're seeing bubbles being pumped into the filter there's a leak somewhere in the system, probably between the electric pump and the fuel pick-up in the tank. Assuming you replaced the parts to cure the poor performance and your carbs are SUs, have you checked the filters in the banjo fittings on top of the float bowls? The float levels are the primary mixture adjustments. An inexpensive Fram clear plastic fuel filter between the tank and the elec. pump will let you know if there's still debris in the tank.

 

I agree, didn't think i had to bleed it either but the bubbles are throwing me off. Previous issue which got me replacing the fuel lines and filter was the debris in the tank and filters. Got that cleaned out as much as we could and now the car wont drive without constantly bogging. Seems like a lack of fuel is going to the carbs. The lack of fuel is for sure the issue in the carbs but i cant figure out why fuel isnt filling up the filter and getting to the carbs. 

[Dat_z240]

45 minutes ago, SteveJ said:

Also, where did you mount the electric fuel pump, and what is the orientation? What does the manufacturer's installation instructions say? What brand/model electric pump did you install?

Electric fuel pump is Delphi (part number FD0037), Orientation is horizontal (exact position as the previous one to manufacture's instructions).

The order is as follows: "Gas Tank" to "filter" to "electric fuel pump" to "filter" in engine bay to the "carbs". 

[SteveJ]

Just to clarify. Do you still have the mechanical pump at the engine?

[Dat_z240]

1 hour ago, SteveJ said:

Just to clarify. Do you still have the mechanical pump at the engine?

Yes, the mechanical fuel pump is still hooked up (new - 1 month ago)

[SteveJ]

What brand pump? There seems to be some issues with mechanical fuel pumps over the last year or so.