I have a 2006 that since it has got cold here wont make over 25 or 26 psi according to edge attitude gauges(usually see 39 to 40) It did the same thing last winter the first cold spell we had. I went to texas last year and it went away and havent had problem since. My egt gets really hot. I think the wastegate is opening to soon in the cold. How could i test to see if the wastegate is opening to soon? what sensers open the wastegate? I assume it has a cold weather safety program until something gets to operating temp.The truck has good power until it needs to boost up then it goes flat and boost stops at 24 to 26 psi and holds steady no matter how hard i push it. Sucks pullin a trailer this way and it gets to hot egts to pull big hills with the trailer like this.

 

Going through the same thing with mine. I actually went under the truck and unhooked the hose on the wastegate actuator and plugged it and had no problems. Boost went back to normal. I did not have any check engine light come on either, but I believe that is because the quad xzt has boost fooling.

I find with mine it starts doing it right around freezing temp. I was wondering if there was a bad sensor, such as intake air temp or coolant temp, that would make the computer keep the wastegate open?

 

Mine did that (when I had the Edge Juice/Attitude a long time ago)

What I did checking it... Took the IAT (inlet air temp sensor) from another truck, hooked it up to my truck (outside of the intake tube, left mine in the tube but not connected) and I put one of those thermalcare heat wrap (for your back or whatever) around it and then taped a towel around that.

It stopped doing it. Until the thermalcare heat wrap wore out (8 hours later) and as I watched the IAT temp on the Attitude monitor, when it started showing cold again (30* it said) it would make way less boost.

I repeated it the next day and same exact thing.

Something in the programming that when its got really cold air coming past that IAT sensor it must de-rate.

 

I think it does have something to do with intake temp. i set the edge to moniter it and if i shut the truck off for 20 minutes or so and turned the key back on the intake temp would be over 100. The truck would run fine up through about 4th gear until intake temp went back below 80 or so. At 13f today going down the road the warmest the intake temp would read was around 40.

 

I'm not sure of the temps and pressures but the ECM will make less boost and fuel less to protect a cold engine. All computer controlled diesel engines have it. Try pulling 67,000 lbs out of the quarry on the first round on a cold morning. 450 hp CAT will pull the hill in 4th but cold it's in 3rd.

The computer is looking at intake temp, oil pressure, and water temp. I know that when the oil pressure goes down and the water temp comes up, they will fuel normal then.