i have an 2005 dodge 2500 with 5.9. while driving it sometimes loses power. when it does lose power if u let off the accelerator to far it dies. it was suggested to me to change the fuel pump in the tank. that didnt fix the problem. then i changed the cam shaft sensor and that didnt fix it either. i have taken it to a local shop and they have put it on the computer several times and it wont throw any codes. if any one has any ideas it would be greatly appreciated.

 

How many miles? Could be your CP3 pump!

 

111144 miles. Wat is a cp3 pump

 

Before you go about replacing any more parts, there' a few things that you can check.

Being that you're asking what the CP3 is, I'm going to recommend that have someone more mechanically inclined do this.....

First, check all your high pressure fuel lines that go from the fuel rail to the head, especially #4. #4 is known to crack this causes a loss of pressure which can cause the power loss and stalling.

Next, remove the fuel lines an check the connector tube nuts to ensure they are properly torqed down. 37 - 42 ft/lbs. This is a critical measurement. Too loose and the tube doesn't seal agains the injector and the fuel goes into bypass. Causing loss of pressure, loss of power and stalling. Too tight and it deforms the tube / injector connection and you get the same condition.

Next, you need to see the rail pressure, both the REQUESTED pressure and the ACTUAL pressure. To do this, it needs to go to the dealer and get hooked up on the DBRIII.

If it's not the fuel line or connector tubes, I'm going to bet that the problem is either A - the rail pressure sensor or, B - The FCA on the CP3 is bad.

 

ok thanks. i also talked to another diesel mechanic and he said there was an injection pressure solenoid on the back of the injector pump that might be bad. i have replaced the #4 injector line about 8 months ago because it was cracked and spraying fuel everywhere. im still drivin it around due to it being the only street legal vehicle i have and last night it started loosing power and would die with my foot on the accelerator. after it died it was hard to start and once i got it to start it would run about 200 feet and die again. after it doing that 3 or 4 times it ran fine. thanks again for the help.

 

That "solenoid" is the FCA (fuel control actuator).

That is one of the likely causes. I would almost guarantee that your problem is either that, the rail pressure sensor or the connector tubes.

To check the FCA, just remove the two allen head screws that hold it in, disconnect the wire harness and pull it out.

Shake the FCA (lengthwise, as it sits in the CP3). You should hear it click. If it doesn't it's stuck and needs to be replaced.

Your best (cheapest) bet is to bring it to the dealer and have them test it with the DRBIII. Paying $65 for diagnostics is a lot cheaper than throwing parts at it.

The dealer will tell you that the FCA isn't available seperately and will tell you that you need a new pump.....not true. You can get the FCA from any Cummins dealer. I you don't have one locally, let me know and I can get you the part.

 

After taking it to a dealer and havin them reset the comp they said it was the injector pump. Thanks for all the suggestions and advice.