Not a steam locomotive. If anything it must be a small puff. I see something every now and then, it's so infrequent that I never even proved to myself that it was coming from me.


Hopefully the chart above shows it. I would say more on the smooth side vs from 0-15 straight up.


the boots are new - from RiffRaff- with a plenum insert. They've been on and off with no significant boost change.

Here's a chart, I can send an email to tugly in a few minutes. This is not WOT - I could not go WOT and keep it in overdrive. The email files will have some passes in 3rd and OD.





Here's a WOT version. I **think** this is WOT 3rd gear and the rpm drop is the torque converter locking up.

 

Correct me if I'm wrong...

MAP-Baro = Boost

Your max MAP is almost 50psi, Baro(?)...assume 15psi. That would make your BOOST=35psi, right?

 

Everything is on the left scale except MPH.

The chart is MAP * 100, so about 24.

In trying to keep it in OD, I would say I was at less than 1/2 throttle the whole time. The max MAP I saw for the entire test was 28.96.

 

Ahhh...

Trying...

 

OK... Rich.... I hate to say it bud, but I'm betting that looks better on your display than on mine. I feel I've been staring at one of those puzzles that end with "Now close your eyes and what do you see?"

I see about 28/29 boost, a jumpy average of 36 EBP on that WOT run - and red spirals.

 

So you don't like my color scheme?

You should have two csv files in your in box (last night) so you can view the data in the tool that's being developed.....

 

Oops.... I thought Rich (white Buffalo) posted that. I know he likes the black background for his graphs as well.

 

Did you guys get a chance to look that the files i sent the other day (to tugly). I assume that based on those files I should still should be hunting down an intake side leak.

I wonder if it can't be found because it's hiding in the cooler. Has anyone devised a good test for that?

I guess could tape up one side of the CAC tube and then tape my boost detector PVC cap to the other side and see if I can maintain 10 PSI or so for a couple of minutes. A leak bad enough to reduce boost would likely leak down fast right?


Any other suggestions?

 

Hmmm If I take off the cold side of the intercooler from the turbo and tape that shut and then air it up through the turbo then I should be feeding a sealed system right?

 

This is one of those times a traditional boost gauge would be useful.

Here's my noob idea: install the boost leak detector on the CAC tube after removing from the hot side of the spider. Removing the turbo and CCV from the pressurized system should allow using higher pressure. Then you can test it up to normal operating pressures, like 25 psi or so. Never did it myself so don't try it until some more edumacated brothers chime in.

Since most things look good but the the EBP is fluctuating, I'd inspect/clean the EBP sensor (use 2 wrenches to prevent tweaking the mounting bracket) and carefully inspect the tube all the way to the manifold. They can rust out and leak. Run some wire or weed eater line thru to clean it of soot.

 

I have a 0-15 PSI gauge.



This is what I did.

1) remove the tube from the air filter and the CCV adapter
2) Remove the cold side CAC tube boot (Passenger side)
3) Seal the cac tube with a plastic bag and duct tape.
4) Install the leak tester in the last tube before the turbo

I was able to pressurize the system, but my duct tape seal couldn't cut it. I need a better approach for sealing up the cac tube. maybe a piece of rubber - like from an old car size inner tube or something.

So my attempt at a kind of leak down test failed. The positive side is that that the only hiss I heard was from my failed cac tube plug.


I've done this. It was clogged and a mess. I cleaned out the sensor and the tube as best i could in the truck. I was able to get weed wack wire to the manifold and verify it by plowing air in the tube.

In addition to the bouncy EBP my EGT readings seem to be able to get higher than expected. I can easily reach 1250 degrees towing ~8,000 libs up a hill in 3rd gear. In addition, it seems like shifting from OD to 3rd produces a raised EGT reading - which is the opposite of what should happen.

So the current thought is that the bouncy EBP is the result of a leak somewhere and this is backed up by the lower boost and the higher EGTs on a stock truck.

 

With respect to leaks, I thought these two WOT charts were educational. The 1st is a known exhaust side leak. See how close EBP and MAP are. MAP is ~29 and EBP is ~30.

The second is a presumed leak on the intake side. MAP is ~28 and EBP is ~35 or more. It also seems like the EBP average is slowing growing and the average slightly increases during the run.

 

The EBP should not fluctuate like that. The PCM is using that info to open and close the wastegate. Can you inspect the exterior of the EBP tube? Kinda hard to get to. They can rust/crack and I can see that causing a fluctuation as the crack opens and closes. Like pinching the opening of a balloon to make a squeaky farting sound to annoy your sister. Also over zealous cleaning can damage the EBP sensor.

For the leak down I was thinking to test everything after the turbo at a higher pressure. The CCV should not be pressurized up to 25 or 30 since that goes thru the whole engine to seals not engineered for the pressure.

What does the boost gauge show? Is it connected at the traditional IAH port location? Does it smoothly plateau or fluctuate? Same with the red line capped off? Stock truck should be able to peg a 15psi gauge.

I vote for the black field on the charts, much easier on the eyes.

 

I have pressure tested and sprayed the EBP tube in the recent past. Lately, I've been on a oil (intake side) and soot (exhaust side) hunt with the camera in places that are hard to see.

I found this, which I will investigate further:




It also appears that it might be getting a little damp there:

 

What are those pictures of I'm curious?