Hi folks...i'm still having an issue towing with my 2004.5 HO. It seems to be down on power since I first bought it last year. It's a stock unit save for the K&N air filter which I have remove and installed a stock one as a test. I have replaced the fuel filter evry other oil change..checked to see if I had any blowby(just removed the oil fill cap..no signs). This morning I check the connections to the Turbo from the air filter hose and noticed it seemed loose....could something this simple be an issue?...I won't be towing again till next race season so it would be tough for me to tell. The former owner stated he had new injectors put in fairly recently and the lift pump is in the tank. It idles great and drives fine when the box is not behind it...any ideas??...The fuel milage is less than stellar also...but it sees mostly city driving. No codes whatsoever...

Also...forgive my ignorance...but what is a CP3 exactly...thanks Eric

 

Do you have a boost gauge?

Sounds like you are possibly losing boost and when towing it is even more noticeable.

The CP3 is the high pressure injection pump. It takes the fuel pressure from the lift pump at 7 to 10ish psi to over 20,000psi in the common rail system for the injectors. It is belt driven on the left side by your power steering pump.

 

The stock CP3 is not belt driven, It is gear driven. It is located near the power steering pump, but aft of the front of the engine.

As far as low on power, are you seeing some measurable decrease in power or does it "feel" low on power? Is the truck a manual or auto trans? How is your oil level, gaining or dropping? What is your empty highway mileage (hand calculated)? Stock tires or larger more aggressive meats?

 

No boost guage...auto trans...maybe 17 mpg on a good day...oil level seems fine...and it use to pull up the hills with a #6000 trailer with no issues...now I have it floored sometimes...Thanks

 

Does the trans seem to be slipping at all?

You can check for boost leaks at all the joints in the piping and the end tanks on the CAC with soapy water and someone in the truck holding the brakes and giving it a little gas while in gear. It will start to build boost and you apply the soapy solution in the spots I mentioned and look for bubbles. Don't "power brake" it for long periods of time, you will build heat in the trans quickly doing that.

 

Nick...the trans seems fine..and once again I was told it had recently been gone through with a new converter when I bought it. CAC?...a bit of help with what that is please..lol I'm use to working on this and it's not diesel

 

Oops my bad. Was thinking the idler pully

 

Eric, CAC is short for Charge Air Cooler. If you follow the discharge from the turbo compressor the pipe will lead to the CAC. From the other side of the CAC a pipe will lead to the intake on the drivers side of the engine. There are several rubber boots that connect all the pipes, and if I recall properly your year truck also has plastic ends on the CAC, the plastic ends are known to leak where they join the aluminum core. I hope this helps.

Rock, no problem. Some twin CP3 setups have the second pump above the PS pump and belt driven. I just wanted to be clear to the OP about a stock set up.

 

having same problem in my 04.5 6spd towing box trailer with two kubota zero turn mowers or a 16 ft trailer with 3 rolls of hay i hit a hill and its a struggle to maintain even 60mph changed fuel filter air filter tightened boost connections replaced lift pump it seems worse right after filling up it even dies at times while coming to a stop once or twice its died while rolling down the road i can take the same loads on the same hills with my 12valve and maintain 75-80mph with ease... what could i have overlooked?