well ive gotten just about everything buttoned up. got a buddy coming over tomorrow to help me figure out why my fuel pump isnt kicking on and i still need to figure out where this goes

 

Good read! I also have a fuel pump not coming on.....I think mine is going to be the PCM has failed. Good luck, keep us posted. Also, I'm digging the green!

 

well my buddy came and helped me work out the electronic bugs with the lift pump... the lift pump kicks on now and i took both of the wires in the last pic and grounded them to the block and the engine turns over but it still wont fire. i cracked the fuel lines open to #1 injector, the fuel supply to the pump and the cp3 line to the fuel rail.

when the key is in the on position the lift pump is running you can hear it hum, there is fuel getting to the cp3 at the supply line coming from my FASS and there is fuel dribbling from the cp3 at the line from the pump to the rail. however there is ZERO fuel coming from the end of the rail leading to the #1 injector or at the line going from the cp3 to the line feeding the rail

i read my engine codes and im getting: PO628 fuel pump A control circuit low

 

Nice build and thread, not sure about the green paint though!


Do you have any gauges on this engine. Low side fuel pressure? High side fuel pressure?

It would be nice to know exactly what the low side fuel pressure at the input to the CP3 is.
If that is ok, it would be nice to know what the rail pressure is when cranking the engine.
Be very careful opening the injection lines as cranking fuel rail pressure is 3000+ PSI and can easily injure you.

The ECM will not fire the injectors (ie. fire the engine) until at least 3000 PSI rail pressure is sensed.
The ECM monitors rail pressure via the rail pressure sensor mounted on the fuel rail.
The ECM meters fuel to the CP3 via the FCA mounted on the CP3.

If everything mentioned above is fine, then the injectors or the pressure release valve can also cause too low fuel rail pressure for the engine to fire.


I think monitoring the fuel pressures is a good next step that will point you in the right direction.

 

I don't have any gauges on it yet other than stock. Getting my edge juice w/ attitude and cts this weekend

But my problem now is that there IS fuel being delivered into the cp3(slightly loosened but allowed fuel to leak out) and there IS fuel coming out the output side of the cp3 headed to the rail(enough to dribble out) at crank but when I crack open the line to the #1 injector or the feed line leading to the top of the rail there is zero fuel on crank... Which means my fuel is being stopped at my cp3 I'm trying to figure out what's causing this.

 

Your Edge CTS should be able to monitor fuel rail PSI via the OBD-II port on your 2004 truck which is excellent.

Again, while cranking the engine you should be getting 3000+PSI at the output of the CP3 and in the fuel rail. BE CAREFUL.

Fuel dribbling out of the rail means zero fuel rail pressure.
Don't forget there are 3 low pressure fuel return lines on these trucks including one from the CP3. Make sure you don't confuse the fuel return line from the CP3 with output of the CP3/input to the fuel rail.

Keep checking for more DTC codes via the "turn key on/off 3 times method".
Double check connections to the fuel rail pressure sensor and to the FCA on the CP3.
If you unplug the FCA, the FCA will default to full fuel flow to the CP3 which will mean the CP3 will max out fuel rail pressure.
This will allow the truck to start but at max rail pressure which is not good but ok for a few seconds of running.

You are really close to getting it running. I hope my info is of some help.

 

I have a code reader which I have hooked up and the only fuel code I am getting is a PO628 fuel pump a control circuit low. I am going to try and unplug the fca and see if it allows fuel pressure that should tell me if that's the problem or not. There's a huge storm rolling through right now so ill have to hold off until tomorrow morning but thank you all the advice and idea bouncing is very helpful

I'm hoping to have my truck running tomorrow so fingers crossed

 

@ stealth. Info is GREATLY appreciated.. I'm SO close to being done with this rebuild its killing me to see fuel making it all the way to the cp3 and not knowing why it's not making it to my rail and not having my baby run

 

My fass (lift pump) also seems to be running significant quieter than it was before my rebuild

 

well i tried unplugging my fca and i still have zero fuel being delivered to the rail

 

im going to pull my cp3 out.. any ideas on what it might be?

 

Sorry to hear that the engine is still not running.

The CP3 is a relatively simple piston pump. Failure is rare.

Did you have the CP3 fittings apart at all? The output fitting with the spring and the ball are definitely installed?

With the FCA disconnected, it should output full pressure as long as the CP3 is turning and it's being fed input fuel.
There is a pressure relief valve also mounted on the CP3.

The FCA should rattle when you shake it, the plunger should be loose.
Perhaps try another FCA before you pull the Cp3?

Failing all that, I can't think of anything else, pull the CP3 and have it tested or swap in a known good one.

 

when i pulled the cp3 during diassembly and reassembly the only things that were removed were the gear nut under the timing cover, the fuel lines going to the pump/rail and the bolts holding pump in. the fca is only 4/5 months old and i checked it and its good. im going to pull the pump tomorrow morning and take it to my local injection shop and have them test it.

 

alright guys im stuck

i took the cp3 to a diesel injection shop here in maryland and they tested my pump and said it was bad so i got to cough up $934 for a new bosch reman.

i got the new one installed and primed all the fuel lines and primed everything up and still couldnt get her to start. my buddy helped me and we messed with the alignment of the banjo bolts and managed to get it to the point that fuel is making to the fuel rail to feed tube lines... a slight trickle/ mild flow.. from what i understand this is a HIGH pressure system and should be pushing somewhere in the area of 3000psi through these lines.. mine is flowing fuel but not nearly 3000psi... with a brand new cp3 what else could be wrong?

 

Son of a... We must be missing something.


If the CP3 is turning, if the FCA is unplugged, if there is fuel input, the output should be 3000PSI+ ...

1. Can the rail pressure release valve be completely failed/stuck open bypassing all the fuel?

2. Can 1 or more injectors be completely failing and bypassing all the fuel?


If you cap off PRV and all the injectors, isolating the rail from everything else, there should be pressure.