I have been having what seems to be a loss of power. I know the tranny is week and am in the process of rectifying that problem.

Climbing slight grade with a 4000 LB trailer, the truck will reach approximately 65 MPH (2000 RPM) and will not accelerate any faster.

Take it out of OD, RPM jump to 26000 and truck will still not accelerate.

Put a manual FP gauge on and it is showing 16 PSI before and after filter @ idle and 9 PSI @WOT.

Boost code was set in puter, Tested boost pressure with OBDII and hits a max of 41 PSI. (It appears that the wastegate is not functioning all the time, However on the highway, I can hear it open and close.

Questions
1) Will the wastegate providing too much boost give the power symptoms that I have been seeing??
2) is there a way to further diagnose the wastegate??
3) can just the wastegate be ordered, I was told by the dealer that the whole turbo had to be replaced??
4) If I have to buy a new turbo, Should I gop with factory HX35 or a larger one?? (I plan on adding a tranny, Injectors, exhaust, and an Edge Comp next month. The gauges will be next week.

Any help would be greatly appreciated

 

From your symptoms, and the code you identified, I would suggest you pull and replace (sometimes you can get away with cleanning the old one) the Manifold Absolute Pressure Sensor (MAP). It regulates the signal to the computer that tells your air circuit when to trip the wastegate. It is found behind the primary fuel filter, and above the lift pump, and is screwed in the side of the head.

If that does not solve the problem, check your Crankshaft Position Sensor (CKP). It will sometimes get dirty and miss reading the tones on the crankshaft and will not allow the fuel to turn up like it should. It is located right under the lift pump and is bolted through the block skirt.

In so far as your other questions about a new turbo and such, it does not sound like you have any problem with any of those components. But, should you decide to go down the performance road, pick a vendor like one of the advertisers here and lay out a plan. They will advise you what you need and in what order to purchase and install the parts.

 

I doubt that a stock truck can make 41psi. RCW is on the right path. Change the MAP sensor. You should see an increase in HP.

 

Thanks much for the responses. Another thing that I did was to hold the brake and accelerate to approx 2200 RPM (Foot on the floor) When I let off of the accelerator, A popping noise is heard like a valve opening and closing. I was also told by the dealer that this is the wastegate trying to open but unable to...

Thoughts??

I will try cleaning the sensors mentioned on Sunday and let you know what happens.

Again, your help is greatly appreciated.

 

Well the noise you hear when doing the brakestand will be turbo bark. More pressure on the inlet side than the turbo will support without exhaust pressure and temperature.

I would just like to clarify that the wastegate is not operated by teh engine electronics. It is operated by boost taken shortly after the compressor wheel.

The Cummins in the dodge will cut off fueling if it sees to much boost. (This is to prevent people with sticking wastegates detonating turbos). So if the MAP "sees" 41psi it will radically defuel you, light the check engine light and cost you some power.
Test the readout of the MAP using the OBD2 against a real world boost gauge.

Just my 2c

AlpineRAM

 

I have had simlar issues and have alot of questions.
What is the OBD2? and where can I get one.
Where is the best place to get a MAP sensor and what should it cost? Please let me know

 

An OBD2 is a scan tool to check engine falt codes via diagnostic port under the dash. You can get a scaner at any auto parts store (ie auto zone, checker, etc.). You can also buy the Superchips diesel tuner it gives you a scaner and a programer for more performance.

Hope this helps.