problem with new reman cp3
 

Today I just put a new cp3 pump in and after cycling the key a few times it fired right up I let it run a little while in the shop and took it for a drive about a half mile and it starts to run really rough and won't start after I shut it off did some investigating and found that I'm getting fuel to the cp3 but nothing out so I'm guessing the cp3 is junk? Or would there be a reason for this?

Could it be pump was not problem in 1st place? Did new pump come with regulator? What prompted pump change?

Yes pump came with a new fca the pump was changed due to only building 7000 psi at wot

Low rail could be to multitude of things. Bad relief valve, faulty rail PSI sensor, and most likely, injectors themselves or transfer tubes in head not torqued to spec. Have injectors been out or replaced?

Yes injectors were replaced about 8 months ago but what I'm trying to say is that I have fuel going into the cp3 supply and nothing coming out while cranking

Unplug the FCA See what it does! Did you torque the nut down on the CP3 gear?

Yes I torqued it

What kind of lift pump? Stock, in tank?

Man, I've been talking to a guy with a Dmax with same circumstances. If you bump the starter, the PCM picks up the no start and will run the lift pump for 45 seconds. Have you gotten the air bled out by loosening the banjo bolts? I know you drove it a little and went rough idle on you, but between fuel draining back while pump was replaced and the air in injection pump from supplier, it's gotta still be bled. If lift pump is working, keep bumping the starter and wait till you have solid stream out of return line banjo. The FCA is a normally open valve I believe so fuel should pass thru and you can bleed rail by disconnecting fuel lines at rail. Set up an old fuel cap for an air fitting with a regulator set no higher than 10-15 psi. Back to basics.

The lift pump is an airdog 150

Is it toggle switch controlled or stock lift pump wiring? Have you bled system all the way to rail and return line as described? You obviously have skills, one line answers don't tell me much. Just trying to help.

I have fuel coming out the supply to the cp3 I can't get fuel out of the cp3 if I could get that it would be no problem but not getting fuel out of the cp3 I won't get fuel out of the return

I have fuel coming out the supply to the cp3 I can't get fuel out of the cp3 if I could get that it would be no problem but not getting fuel out of the cp3 I won't get fuel out of the return

Man, you are describing a classic air lock problem. Please don't be insulted by my remarks. The return line is there for what fuel doesn't go thru rail. The pump itself is air locked and the rail also. The return line banjo on pump will bleed the air out of the pump and loosening the injector lines at rail will bleed the rail, try it please. VP44, P pumps, VE pumps all had to do the same procedure. Even individual pumping units such as 2 cylinder Lister Petter engines had to be bled at injectors to get started. I worked for Cummins for 14 yrs and had my own shop for 15 yrs where we rebuilt 15-20 CR engines and replaced 5 or 6 Dmax CP3s because they don't use a lift pump stock and the CP3 overheats, destroys themselves. It's only a little time wasted and everything is easy access if I'm wrong and I will apologize to you. The reason I asked about injector replacement is maybe the injector cross tube retaining nuts need retorqued. ??? It might be just the rail that is air locked since it already has been run. If the pump was faulty or broken, then you wouldn't get fuel out of pump return.

So your saying just loosen the return banjo on the cp3 and the injector lines and keep turning the engine over to bleed out like older models? Because I took the supply line from the cp3 to the rail off and no matter how long I crank I get nothing by the way I appreciate the help

Yes, but just 1 at a time. Return line first, and if still nothing, stop there. Need to verify you have lift pump pressure while cranking. I checked out Air Dog's web site and they do use PCM commands to actuate relay for power to LP. I'm thinking since you got more air in lines than ever, it all ended up in CP3 and rail at about the time it went rough idle on you. But that was for newest Air Dog kits, if yours is an older kit that runs off of ignition run circuit, it wont run while cranking. Check it out.

First thing to check is if it will fire and run with starting fluid of some type. If it will start and run you have a leak somewhere, if not then back to checking fuel supply.

The CP-3, injectors, and rail are self air bleeding. They simply cannot air lock due to the design. If you have fuel delivery to the CP-3 inlet constantly while cranking and nothing is coming out to the rail it could be FCA or even the COV stuck wide open. Check your CP-3 return line when cranking for fuel flow to see if it actually getting fuel thru the CP-3.

Well guys after coming to the conclusion there was something messed up inside the pump I pulled it and took it back to the shop I had gotten it from they spun it and found out there was something up inside the gear pump so now once I get this new one in we will be back in business thanks for the help once again guys!