Truck idling problem

[draymorris]

For about 2 months now, my truck tries to dies when idling - sometimes. The ECM keeps it from happening, so when this occurs the engine will lug, then pick up to about 1300RPM, then repeat. At first it only happened when the engine was cold(first started), lately it has become a common occurance and has begun doing it when I take off from a stop sign even when the engine is at temp(sometimes). I have had one Dodge tech tell me that the fuel pump probably has worn and has a sticking valve.



Also, I get more black smoke than I have before. Since I have no mods on my truck, I usually don't smoke at all.



I have 135k on the truck, and they are hard miles, so lots of fuel has gone thru the engine.



I have run power services additive, 2 cycle oil, and now I use Lucas because it gives me better MPG (though it does not seem to effect my problem)



Any input will be appreciated.

 

[rbattelle]

Wow, could be lots of things. Like the tech pointed out, I blame the fuel system. That doesn't narrow it down much, though. Have you changed the fuel filter at the recommended interval?



Didn't someone complain about a similar problem and it turned out to be either the rail pressure sensor or the fuel control actuator on the CP-3?



-Ryan

 

[jelag]

My 04 had the same problem at around 90K miles... . Dealer finally found that the lift pump had started to fail and the result was the high pressure pump was bad... . seems lack of fuel in the system allows for some of the parts to wear from lack of oil... and part of these parts in my case were the parts in the high pressure pump that contols return fuel... .



They put several sensors on the truck first and finally correctly found and repaired the problem... . If you have the same problem that I had expect a 1500 bill... . mine was covered by warranty... .



I than went out and purchased a Holley Red pump and wired it into the existing pump circuit with a relay and mounted this pump by the fuel tank... . Now at around 130K every thing is still fine.....



Jim

 

[draymorris]

So it sounds like I should first see if I have pressure from the transfer pump, if not replace it, then go for the pressure pump.

Did the Holley pump replace the factory transfer pump?



Thanks

 

[Big_H316]

draymorris, I know exactly what you're talking about. Mine did the exact same thing for over 100,000 miles. Dealership wanted nothing to do with it and finally at 166k the lift pump went out and finally at 188k I had to replace the CP3 because of a faulty solenoid on the side of it. You can't just replace the solenoid either, gotta change the whole pump.



I have detailed instructions when you get ready to do the change... . very easy and straight forward. I bought a re-man unit from Dodge for $930 out the door. Cummins can get you a brand new one for $1400 but they're on back order. Easiest bet is to order one straight from a Cummins shop, They quoted me $1100 about 2 months ago but it would have to be ordered as well and at the time I replaced mine Dodge had one in stock... imagine that!! Good luck on your quest.

 

[rbattelle]

You can't just replace the solenoid either, gotta change the whole pump.

That's the fuel control actuator. I think a fundamental flaw in the design of the CP-3 is the inability to replace that actuator without replacing the entire pump.



-Ryan

 

[Big_H316]

I talked to a guy the other day with the same problem and he went to a wrecking yard and pulled the solenoid off of another '03 CP3 and has had no other problems. Not sure what he paid for it but it was a vehicle with the engine still in the truck... he must have known the owner of the wrecking yard to be able to pull that off. My luck, they'd make me pull the whole pump and still charge me full price for it.