Please help me diagnose my boost problem

[jelag]

Someone help me here..... I don't understand how a dealer can pressure test the intake system without special tooling and I've never seen it at my dealer. . someone help with this... .



We've had 2 or 3 problems like this and all of them have been loose hoses or clamps on the pressure side... 2 times on one truck after the dealer did work on it... . They did some body work... . and in the process of doing this they had to remove the hoses on the inner cooler... . and left them loose... as reasonable speed we never noticed the problem... . as we needed power it just wouldn't go there... we don't have any gear on the engine... we drive them stock... .



Hope this helps...

 

[Cattletrkr]

I didn't question how they tested it, they just said they did. I would imagine you could take the hose off the turbo that goes to the intercooler and the hose off the intake horn and pressureize between the two. My problem was/is sporadic so I really don't see how it could be a leak anyway.



I pulled the chips for a few days now. It's running a little better. Yeah, outside temps were in the 30's and low 40's the last couple days, that helps. Still not good enough though. Nasty rough idle is back too. That shoots any good I may have hoped to get from replacing the FCA.



There's no rhyme or reason to the rough idle either. Tonight it was borderline surging when I got home. Earlier today it was fine. One start I had to crank extra long before it fired.



Other than stranding me with another blown CV jointon the front driveshaft last night, this thing just keeps going. All these stupid quirks and no codes or lights. #@$%! #@$%!



CV joint ws fun. Kept me up until 3am this morning, and now as you can see another late night. Had to haul the truck home last night... couldn't get the shaft off in the Target parking lot. Dad's '03 to the rescue.

 

[KDillard]

well since the temp have been above 40 all week on the way home I havent had the low boost issue. Maybe a glitch in the PCM??? Never had a flash and the truck was made in jan of 05.

 

[Cattletrkr]

Mine is up some, but not where it should be. I'm waiting until I get off winter fuel to decide for sure. Then I'll put the chip(s) back in and see if I can go higher.



My idle is getting rougher and the skipping is more regular. Sooner or later it might be bad enough to take it in and find something.

 

[Cattletrkr]

I'm gonna try getting the truck flashed next time I'm near my dealer. Truck is skipping almost steady now. Ususally going downhill with the cruise set, but also uphill some and even with thee cruise off... just not as noticeable.

Low boost problem is gone now that it's warm here. I guess this problem is on the back shelf until fall.

 

[APacitti]

I have been having the same issue over this past winter with my 05 and it seems to be much worse with the juice installed. In march i also drove from IL to AZ through Colorado with a car in tow and was able to observe several things during the trip. Anytime the temps were below 50 degree i had boost issues, the entire time i was in AZ (4 days, 75 degrees or warmer) i had no boost problems at all. Now heres the interesting part, I was also at 6000 + feet in Colorado at well below 50 degrees and i had zero boost problems. Now my theory is that its not so much a temp issue and more about air density, i don't know what if anything in the truck measures air density but it seems like it messes with the truck, especially trucks with the juice installed and this would also account for edge not being aware of the problem as there facility is also at altitude. I hope this makes sense. Perhaps someone can expand upon this idea.

 

[Cattletrkr]

Our trucks do measure baro pressure. I've suspected it has something to do with that all along, but I have never been able to log any data to back anything up. My truck used to be goofy whenever the weather changed, regardless of which way the temp went.

I think the latest update does have something in it to do with the baro sensor, but I don't remember for sure.

 

[BMH95]

I know this is an old thread, but I'm wondering why my '05 only spools to about 26-28 lbs before the wastegate opens. I did see a brief spike to 30 lbs Sunday, but can't replicate it. I've got an auto with 373's that is stock.

 

[Jason Griebel]

I'm glad you brought this back up my 2 gen is doing the samething and out of reading all the posts juice w/ att. is what I see in common I even wired the wastegate closed and it still did it. I'll 25 psi and the truck starts to jerk usually build 35-38.

 

[hotram03]

Cattle the sensor in the Air intake is a Map sensor it does Baro & incoming air temp, the other map is located int he inake manifold by the fuel rail, its does Boost and Baro. You can take some air line and install a gauge with a regulator, unhook the wastegate hose going into the actuator on the turbo, hook up your airline and slowly give it pressure all the way up to 30-35 psi and wastegate should operate in all ranges opening and closing as you back off psi. this will confirm mechanical operation of wastegate, not the electronic portion.