Pump builder unite, Ive gotta story.

[ORCoaster]

I would check both the regulator connection and the closing of the 12-volt controlled valve.

[fatmobile]

"I can see fuel slowly draining from to return to my bottle."
Not sure what that means.
Sounds like you are bottle feeding it.

It's probably just siphoning downward.
Are both ends of your hoses under liquid so they don't let air in?

[libbydiesel]

If both supply and return were submerged then if it siphons down, that indicates that there is a leak in either the fuel lines or the seals of the pump itself. 

[Tomoturbo55]

"I can see fuel slowly draining from to return to my bottle."
Not sure what that means.
Sounds like you are bottle feeding it.

It's probably just siphoning downward.
Are both ends of your hoses under liquid so they don't let air in?

I was measuring just the return flow to the bottle, in the "internal pressure pump" thread it said to be around 0.417 liters per minute.

Hope that cleares things up.

[Tomoturbo55]

If both supply and return were submerged then if it siphons down, that indicates that there is a leak in either the fuel lines or the seals of the pump itself.

It has a leak from injector to injector Line so that could be the problem thanks. I think seals are fine because i have no leaks on pump

[fatmobile]

It's quite possible that if you only have the input in the fuel tank that it will continue to syphen back to the lower tank.

Unless there is a check valve in the input line.

[Tomoturbo55]

It's quite possible that if you only have the input in the fuel tank that it will continue to syphen back to the lower tank.

Unless there is a check valve in the input line.

What is check valve, i have non return valve fitted to imput Line fitted.

This also happened to me on last car tryin to adjust regulator, but now i get Like missfire on cold start.

[libbydiesel]

If you have a leak in any of the lines, the fuel syphons back to the tank.  That results in the pump no longer being full on cold starts and so the cold starts can be hard and the engine can miss. 

[fatmobile]

Got clear fuel lines to and from the pump?
If you are getting a missfire on cold starts it could be fuel syphening back
which you would see in the clear line.
 Or the timing might be retarded.
 Does it still stumble with the cold start lever pulled out?

[Tomoturbo55]

I have no more leaks anywhere, but it still siphons back to tank after few seconds, even checked 12v solenoid o-ring is fine its all tight and good.

So maybe its regulator, does anybody know how tight it must be, some torque Spec?

[libbydiesel]

If it siphons back to the tank, then you have a leak that is letting air in.  It really is that simple.  Sometimes a leak will allow air in without letting diesel out. 

[fatmobile]

So after a few seconds you see air coming out of the pump heading back to the filter?
If so.
Do you have a vacuum gauge on the front of the pump to see how hard it is pulling fuel?

[Tomoturbo55]

Well, I tightened the regulator as much as I could. It is much better now. I saw fuel going back to the tank slowly.

[fatmobile]

Still wonder if it is the mainshaft seal.
Even though you said there was no foam coming from the injection pump heading back to your tank
 that you can see through that clear line.
 Like the regulator, behind that seal is connected to the front of the pump too.
 And is close to the front of the pump so would show air soon after shutdown if it was leaking.
You could probably put some vasoline or diesel, WD, etc. on top of the regulator and see if it's getting pulled in.

[Tomoturbo55]

It's not getting pulled seems like my LDA was the problem.
My throttle shaft inside the pump managed to break somehow. Luckily not one spring fell inside the pump.

So I was forced to use n/a top cover and throttle. Even when I have a fuel leak on the throttle o -ring.

It starts with just 3 turns of the engine when cold when hot just takes 2 turns.

But my LDA top cover did not leak fuel outside or when taking the pin out, it was all dry.