Dual cp3's and no rail pressure???

C

cumminsX

Can't make up my mind
Joined
Apr 7, 2008
Messages
447
I just went to dual cp3's on the new build and I put a used d-max pump on top. Things worked ok for a while and then I got a grinding noise that sounded like it was coming from the d-max pump, it got pretty loud and then went away. I drove it around after that and it ran good for about a half hour and then it got real smokey and lost a bunch of power. At first I thought it must be a boost leak, but I looked at the rail gauge and I was only hitting about 17,000 psi max and it would fall to around 10,000 when I would give it any fuel. So now I am not sure what to think, I took the harness out of the loop and just plugged the bottom pump in to see if it would build pressure and it was the same. Any Ideas what I should check next?
 
also the top pump feeds the top of the rail with a dual feed line, so there is no rail relief valve.
 
well I am running out of ideas, I have checked the FCA's, changed the rail pressure sensor, tried running it on just the bottom pump, and a few other things. Does anyone know what would be sending the signal to the pumps to ramp up pressure? Is it only the ECM? I have loaded a few different programs with the Smarty and no change. I am setting it back to stock now to see if that does anything. I have just enough pressure to get the truck started and then it gradually comes up to about 8000 at idle, then crusing pressure is between 15,000 to 18,000. If I give it any pedal it drops back to 8000 to 10,000 psi? Anyone???
 
It is Industrial Injections kit, but even when I take the controller out of the loop it is the same so I am thinking it must be something that has to do with whatever sends the signal for the cp3 to ramp up the pressure.
 
BgBlDodge said:
Dead pump?
Click to expand...

it runs the same on just the bottom cp3 and it was a good pump on tuesday last week when we pulled it off of the other motor. Also I had good rail pressure when we first got it going and then it just went away, I had to change the oil pressure sending unit and I don't know if maybe I bumped the harness when I was reaching in there but I don't see any loose wires or grounds.
 
I did and they said to check the lift pump pressure, it is a steady 17psi from the airdog. I might have to call them again tomorrow.
 
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