05 LLY Boost Problem

[tanman_2006]

Truck in question: My cousins 05 LLY/allison crew cab dually 4x4 w/ bale spike flat bed, KNN cold air (he wont change to dry flow), 5in exhaust, edge w/ juice, 187K miles. My uncle bought it from the Dealer with 30K on it and the dealership used it to haul their cars. My cousin got the truck 2 years ago.

The truck had been leaving a steady fog of smoke while cruising since edge was installed at 20K miles (reason the dealer sold it). My uncle figured it was normal since it had good power when you leaned into the happy pedal.

Edge programming update cured it 75% of the time. MPG went from 11 highway to 16-17 highway

Now the truck has low power and wont boost past ~8PSI (setting doesnt have any effect and neither does load) unless you floor it then it will hit +22psi. When the boost sticks at 8psi it smokes pretty bad even cruising.

After you floor the truck runs normal with little to no smoke and boost builds freely.

Is the turbo gummed up? Is there a sensor that could cause these symptoms?

 

[btfarm]

Vane position sensor could be bad Tanner. I don't know alot about it but do a search on the LLY/LBZ forum and it might show up. One of the guys changed his a year or so ago.

 

[Ed HD]

/offtopic, but he doesn't need to change to a dry filter. For dusty environments, an oiled filter is better, just needs more maintenance.

Also sounds to me like a vane sensor.

 

[tanman_2006]

Thanks for the input. I will give the vane sensor a shot before we dive into a new turbo.

 

[3500GMC]

EGR tube cracked/seperated? See Soot?

 

[btfarm]

Check the CAC connections and clamps. They've been known to pop apart on occasion where the blue hose sections are.

 

[tanman_2006]

EGR tube cracked/seperated? See Soot?

Since we've owned the truck we have chased the EGR as the source, it was last replaced at 165K so i doubt it is the problem.

Check the CAC connections and clamps. They've been known to pop apart on occasion where the blue hose sections are.

It has new connections and clamps, they blew last summer.

 

[WarWagon]

/offtopic, but he doesn't need to change to a dry filter. For dusty environments, an oiled filter is better, just needs more maintenance.

Also sounds to me like a vane sensor.

Are you taking these readings from a scanner or boost gauge? It is relevant to my first suggestion.

MAP sensor plugged solid?
Possible crushed exhaust pipe?
Plugged or melted converter?
MAF sensor dirty?

The LLY injectors do not last forever and the white smoke is an indication of injectors. So is an idle surge after the FPR has been ruled out.

:rant: Sorry, I really have good reasons to dislike these filters.

With the EGR dumping soot into the intake and the PCV adding oil to glue it together the intake looks fairly nasty past the EGR. The last thing these trucks need is the fine dirt that gets through the oiled filters adding to the mess. Most dirt will blow through the engine and could help cause trouble via gritty build up in the exhaust section of the turbo. I have already walked when the oiled filter dirt built up on the idle air control valve, 2002 5.3L gasser, and the engine would not idle. (This was used on a 1 mile dusty dirt driveway and paved roads. Failed the part before the 36K warranty was up and had a fingernail thickness of dirt built up on the plunger.) My jet boat with the Coast Guard approved K&N also had a nasty dirt build up on the carb and you could never keep oil on the top of the filter as it ran down to the bottom - white on top and pink on the bottom while pulling in oil to grime up the carb. Jet boat normally has a flame arrestor and no filter. I would say the same net effectiveness as only a flame arrestor for K&N but you have to clean and reoil the K&N more often. Much more oil movement in the filter possibly due to our 115+ degree weather while sitting all week. Not that underhood air intakes temps are much cooler...

The LLY trucks have a MAP sensor that is difficult to get to. These plug up with the oil/soot mixture and get burned by the heat as they are past the EGR getting maximum dirt and heat. Adding extra dust to plug them up... Well I would check this sensor for proper operation. They plug up solid just on OEM filters from soot and oil.

 

[tanman_2006]

We are getting boost #s from the edge display. There is not any white smoke, its black as coal.

Is there a way to check maf and map readings on the edge as a scanner?

 

[WarWagon]

Boost readings would be from the MAP as I recall.

On the not enough air thought. Maybe block the EGR just for testing if it wasn't blocked already. I drove a 2007 with a tuner on it. It coated the trailer in black with a cloud and wouldn't move from a stop hardly. After it got some RPM it would run like a scalded cat. It never really ran all that good. I watched vane position and boost on the tuner it had. Forget what one and your year may not have this info.

The owner finally blocked the EGR from a blocker plate I gave him months ago. The cat and DPF were already removed due to plugging up.

Night and day smoking the tires from the light and no black smoke.