[Boostmonkey]

Last week I installed my gauges and I am only getting 15-16 psi @ WOT, the other posts I have read, most people are getting 20-22 psi @ WOT, I checked all my CAC tubes to make sure they were tight, I even tried the gauge grom my 'burb with the same results, could there be something wrong with the truck? Or is there any adjustment that will control boost or limit boost? Sorry for the long post, this is my first diesel so I am trying to learn, thanks for the help.

Rob

 

[Cobra#3747]

I see around 24 or so. Will see more boost in the higher gears when there is more load on the engine. When are you looking at the gauge?

 

[Boostmonkey]

I tried it from a stop and rolling about 40mph it did spike once to about 19 psi at around 75mph but I couldn't make it do it again, both time were lightly loaded, I also noticed some smoke. It wasn't thick black smoke but it was noticeable in the mirrors.

 

[Jazman]

Where is the probe??

 

[Boostmonkey]

aluminum elbow

I put the line in the cast aluminum elbow on the passengers side going to the engine.

 

[Boostmonkey]

right here



right here

 

[Cobra#3747]

close to the same place I put my fitting. I dont have the cat, so that might make a small difference.

But I have found that the boost does fluctuate being the VVT turbo

 

[Boostmonkey]

I still have the cat but the muffler fell off. When I added the exhaust to my suburban I lost about 1 psi of boost I figured it was due to less back pressure or the air was moving thought it faster, I did pick up a few grams/sec going through the MAF at WOT, I should be getting the software for my genisys this week, could it be a skewered (sp?) sensor limiting boost? The suburban is a blown gasser, so I don't know if this will work the same way.

 

[2006sierra]

I am also getting 23-24 lbs. of boost at WOT. It hits this in almost every gear at the hight rpms right before shifting. Is it possible that your gage is bad? Or perhaps the vacuum line is crimped at some point giving you false readings? (I see it is mechanical) I am sure you would notice the truck would be a dog if you only had 15 lbs of boost. In my opinion I would check the line and possibly return the gage and see what happens. JMO.

 

[Boostmonkey]

I swapped the gauge from my suburban and got the same results so I would say the gauge is good I also capped the end of the tube at the engine and drew a vacuum at the other to see the line was cut but it held 10" vacuum for 15 mins so I don't think thats the problem, I am going to recheck all the CAC hoses to make sure I didn't miss anything. Could the air filter limilt boost? Not being able to draw enough air, the truck only has 1500 miles and the filter looks clean, I am driving myself nuts tring to figure this out.

 

[Boostmonkey]

Fixed it!!!

I was messing with it so more today, all the conections were tight I checked the plastic elbow coming from the CAC, when I pulled it apart the rubber/plastic seal was crooked (sp?) I put it back together with a little biolube (spit) and now I am getting 20-22 at WOT and 5-6 psi cruising, the truck also runs a little better, thansk to all who helped.

Rob

 

[DMAXSHAWN]

25 psi @ WOT every time would like to see 32 to 34. I guess I need to call Mr Kennedy