???CP3 pressure when cranking???

[dan shss]

How much pressure should the cp3 have when just cranking the engine over? My truck died and now wont restart,I have plenty off fuel and pressure on the supply to the cp3,but when I unhocked the high pressure line comming from the cp3 to the bottom of the common rail and then I crank the engine over im just getting a very small amount of fuel comming out of the line . .

Is this normal our should fuel be squirting out of the highpressure feed line while cranking the engine over?

This is on the 03 in my sig.

 

[jwilliams3]

You should have plenty of fuel coming out of that line that you disconnected.



Sounds like a problem. Maybe the rail sensor that helps command fuel from ecm has went bad?

 

[John Robinson]

The ecm will be requesting 5800 at start up. I have found that it takes at least 4000 lbs before she wil start.

 

[dan shss]

I guess my cp3 is bad then because the fuel was not even squirting out of the high pressure line ,it was just barely flowing out .

 

[John Robinson]

No sir, I bet your pump is ok, All your pressure is leaking off thru a injector or combination of injectors.

 

[AMassaro]

Isn't it dangerous to do that?

 

[dan shss]

No sir, I bet your pump is ok, All your pressure is leaking off thru a injector or combination of injectors.

I think you mis understood I have the high pressure line comming from the cp3 going to the bottom of the fuel rail unkocked so the injectors would not be a factor at this point. . then when I crank the engine over fuel is just barely comming out of the line

 

[dan shss]

Anyone else have any more input?

 

[Floor It]

You only need 1500lbs to start the common rail motors, there is not that much that comes out at start up but you could have a problem with the FCA on the pump. Try unpluging the electrical connection on the pump then try and start it, if it starts it will probably rattle alot so shut it off pretty quick. That will let you know if its the FCA or another problem somewhere else.



John

 

[dan shss]

You only need 1500lbs to start the common rail motors, there is not that much that comes out at start up but you could have a problem with the FCA on the pump. Try unpluging the electrical connection on the pump then try and start it, if it starts it will probably rattle alot so shut it off pretty quick. That will let you know if its the FCA or another problem somewhere else.



John

Thanks John I will go try that.



Dan

 

[dan shss]

Ok I upluged the connector and the truck did start and the engine did rattle just like you said. So the next question is can you unbolt the fca off the cp3 our is it inside the pump. Thanks again for all your help.

 

[sag2]

It has two screws that hold it on. Unplug the connector and remove the screws. It should pull straight out. Look carefully for rust or debris that might be on the end of it. I believe it should click when you turn on the key. Do it removed so you can feel it click.

 

[dan shss]

Thanks for the help everone ,I should get the new FCA wednesday our thursday and then hopefully that does the trick. I will post my results.

 

[TCluff]

It has two screws that hold it on. Unplug the connector and remove the screws. It should pull straight out. Look carefully for rust or debris that might be on the end of it. I believe it should click when you turn on the key. Do it removed so you can feel it click.

the fca has 3 torks head screws

 

[dan shss]

Update!! The fca did not fix my no start problem. . Ive unhocked my tst box still no start. If the fca is unpluged the truck will start our if I clamp off the fuel return line going to the cp3.