Check valve in fuel feed lines to injectors?

[Blakeo]

In the engine bay I replaced the fuel feed line that goes from the fuel quick connect, to the fuel line dampener. I also placed an aftermarket fuel filter inline which is rated for EFI. 

The issue I'm having is when starting the car will cough a little bit, until fuel pressure comes up and its fine. If you turn the key once before starting to prime the fuel system, starts no issue. 

Issue only started to happen after I replaced this line, so I'm thinking there's either a check valve in there or my fuel filter has added capacity it has to fill so needs to prime longer? 

Unfortunately I had to install the fuel filter to protect my new injectors, the fuel tank was rusty and stuffed up the old fuel system. I had to buy a new tank, new pump, injectors, replaced all soft lines and cleaned out the factory hard lines. 

Any suggestions? 

Thank you.

[Murray_Calavera]

What fuel pump did you end up using? The old check valve would have been built into the pump and it sounds like your aftermarket fuel pump doesn't have a check valve. 

If your going to install a check valve, I'd install it as close to the fuel pump as possible. 

[sonicii]

I would be concerned about fitting anything after the fuel pump regulator, the ECU assume the fuel pressure at the pump is the same as at the rail in a returnless system, adding components between the 2 points could introduce a restriction and therefore a fuel pressure difference, which will cause issues.

[Ben C34]

56 minutes ago, sonicii said:

I would be concerned about fitting anything after the fuel pump regulator, the ECU assume the fuel pressure at the pump is the same as at the rail in a returnless system, adding components between the 2 points could introduce a restriction and therefore a fuel pressure difference, which will cause issues.

Check valve will drop pressure so little there's no way it would matter.

[Blakeo]

On 2/19/2021 at 4:19 PM, Ben C34 said:

Check valve will drop pressure so little there's no way it would matter.

I think he means because I've installed a inline fuel filter before the fuel rail it could be causing a restriction which is pretty likely. Full send though.