I have read many threads but can't find any that seem to address my problem. I am new to Cummins electronics and could use some help on this one. Brief history: 2005 Ram 2500 4WD Truck comes into the shop with no engine in it and a bed full of parts. Back seat is full too. Owner says the old engine got too hot and a Reman long block is on the way. Long block arrives and I put it in but now it won't start. The only thing I can see is it's not getting enough rail pressure. So I put the Auto Enginuity scanner on it and based on the readings I am getting I have more questions than answers. Maybe someone can help me out. With KOEO, the fuel rail pressure jumps back and forth between 49.5 and 84.9. When cranking it reads around 113 or 114. The FCA amps shows 0. When I stick the FCA connector with a DVOM and key on, it shows nothing. Unplugging the FCA has no effect. Not sure what this means exactly, but the fuel rail voltage shows 2.03 volts with key on and 2.07V when cranking; the fuel rail output shows 0.0% with key on and 35.3% cranking. Where do I go from here? Thanks in advance.

 

Whats your fuel rail pressure while cranking? You must see around 3800 psi before injectors will fire. Hopefully, here's a link that will help you with this problem. Dodge Cummins diesel diagnostic repair and service info for Dodge diesel pick-up trucks courtesy of Oregon Fuel Injection

 

Rail pressure when cranking is about 114 psi. I am now getting 2.3-2.8V to the FCA with key on, and about 1.0V when I probe the FPS connector with it connected to the sensor. Can't find any wiring diagrams that match this truck. The '05 and '06 FSMs both show 3 wires to the FCA and I only have 2???

 

The fca will default to full pressure, if it doesn't see voltage. You need to find out why you don't have rail pressure. If you don't see at least 3800 lbs of pressure the ecm will not fire the injectors.

 

Fuel return flow, according to the link you gave me ssteve58, is supposed to be 90 ml/min at cranking speed and I am getting 1100. The CP3 is putting 500 ml/min to the rail. I am still checking for flow from the head, the relief valve and the return side of the CP3. Thank you very much for your help!

 

My latest findings are: 1.5 litres/min at cranking speed out of the CP3 fuel return line; nothing from the cyl. head return line; nothing out of the pressure relief valve. I think I have enough to condemn the Cascade Overflow Valve and find a replacement. Thoughts anyone?

 

Have you confirmed that the lift pump is working properly and you are getting enough fuel flow and pressure to the CP3?

 

The flow seems great. I could run a pressure test. Do you know what it's supposed to be? I haven't found any normal value for it. Someone said 7 psi, is that right?

 

The line that you are suppose to be checking on this test comes from the cp3 and goes to the rail where all the lines that attach to the connector tubes come from. The acceptable volume is 70 to 90 ml (2.36698 to 3.04326 oz) in thirty seconds of cranking, any volume less than that condemns your cp3 or a part of it. I really don't know where your getting 1100 from.

 

Pressure from the lift pump should be around 10 PSI although it can drop to zero under load and heavy towing. It's the volume that's important.

 

I got the 1100ml/min. by disconnecting the fuel return line at the frame-to-filter quick release fitting, and then connecting a tube to the engine line and running the tube into a jar. Taking a sample at that point tests the entire system. I then checked the volume from each component individually to isolate the source of the excessive return fuel. I found it was coming from the CP3 fuel return line, and this time I got even more volume - 1.5 litres/min. at cranking speed. Subsequently, I have ordered a replacement Cascade overflow valve. I will check the pressure and volume of the lift pump however, just for the record. And I will post those findings when I get them. Thanks again for your help!