F115TLRD fuel pump replacement

[99yam40]

my only thought is if the pump can pump 100 when out of the system, then something is dumping fuel and not letting it build up the proper pressure or something is restricting the fuel coming into the pump.
I would guess the regulator, but that is just my guess.
if injector was stuck open it would be flooding the cylinder

[boscoe99]

Update, the aftermarket fuel pump that tested bad ,going by psi 's, that I replaced ! It tested 100 psi off boat but could only get 28 max testing it at fuel rail and before fuel rail.
The screen is clean on fuel pump ,changed filter and water separator, fuel hose, plugs and fuel pump and van not get 40 psi's
Any help , I would be thankful for.

What controls the fuel pressure?

[Robertzoo]

The regulator at the top of the fuel rail, controls the fuel pressure,
I got it apart now and found a piece of trash in the needle the controls the flow. I'm looking for some kind of restriction I can't find it. I'm going to try to test it couple different ways,
what I read the regulator hardly ever will go out. I don't know what the deal is I'm going to look into it further

[99yam40]

The regulator at the top of the fuel rail, controls the fuel pressure,
I got it apart now and found a piece of trash in the needle the controls the flow. I'm looking for some kind of restriction I can't find it. I'm going to try to test it couple different ways,
what I read the regulator hardly ever will go out. I don't know what the deal is I'm going to look into it further

if you found trash in the needle and seat, that would not let pressure build up and would cause pressure to drop to 0 as soon as the pump turned off.
is that not what you are having problems with

[Robertzoo]

Update!
After finding trash in needle, and the pressure air bled on the part that fuel pump is in and putting the rubber gasket on fuel put it self on different. I had 41 psi.
put all together and same Sh**, but now I can get 31 psi and will hold 31 psi on fuel rail! Now, I see the regulator psi decrease and increase 3 psi when I'm hook it up or unhook it!
I ran new fuel line to gas can to the filter on the black of the motor , nothing changed!! However, my primer bubble is not staying pumped up or can I pump it up to stay hard and only thing that could RESTRICT or leak is that rubber gasket on top of fuel pump inside the box the pump is in!
I keep finding air in the fuel box that the pump is in, has a place to get the air out of the fuel system.

is my low pick up pump out? It pumps gas out but not checked psi on it, do not know what they should be?
that rubber gasket that compresses down on the pump it self has to be one of my issue's. I feel it's leaking inside of the box the fuel pump is in!

[Robertzoo]

Up date, my low psi was from the rubber boot on top of fuel pump inside the case the fuel pump is in, I guess it was leaking inside the case,
now I got right psi something is keeping it from running right, I can only get 4,000 rpms ,
new plugs and all get fire,
my pump bubble will not ever get tight,
is this a low pick up issue, something inside the tank, almost as it's leaking air but it's not?

[99yam40]

what is the rail pressure when the problem shows up?
are you talking about the primer bulb will not get firm when motor is not running?
or when it is running?

[Robertzoo]

Both ,primer bubble not get tight, however this morning it was tight running or not, did not change anything, used gas can,no change
key on 41
running 38
it will only hit 4,000 wide open

[99yam40]

so the pressure is too low when it is running 4000 and limited?
what does it read when running lower than 4000?


I would say you still need to find out why the rail pressure is not in spec