I have low power at WOT but otherwise normal performance. I made a couple data files but I am not sure exactly what to look for. Any advice?
I made a dumb mistake and put gas in the truck a couple months back. So ! did a few things while troubleshooting that issue.
1. New passenger side valve cover gasket. The connector failed years ago and I wired it together so I thought why not.
2. Cam position sensor.P0340 code.
3. Injector pressure regulation sensor. Had oil in it.
4. Exhaust Back Pressure sensor and tube clean. Read 23 psi on cold dead engine.
5. Hutch mod. Had air in fuel so I dropped the tank to replace lines. Hutch was preventative but my screens looked new...

I'll post a chart of my data when I get it charted.

 

Look for boost leaks...black soot at the up-pipe joints on the firewall. Is there any black smoke when you're in the peddle at w.o.t.?

 

It sort of hits a ceiling at 2400 RPM. Almost acts like a governor.
The max ICP(psi) is 2754.6 and max IPR(%) is 35.55. Max speed is 62mph. Overdrive off.

 

No smoke. I'll look at the joints.
Would MAP or MGP readings indicate boost leaks?

 

If that yellow trace is correct, your boost (MGP) is way low for a WOT run. That's showing 7-8psi? Maybe it's defueling then if no black smoke, due to the low MAP. I agree with bwguardian - time to hunt for exhaust drive pressure leaks and boost leaks. MAP/EBP does look low, but not sure with the units on the chart.

Could you attach your raw data so we can play with it in excel a bit?

Love your use of a log scale to spread out all the PIDs on the same chart - very nice!

 

They are saying something isn't right. You're only reporting 8 psi of boost at WOT. That's not gonna get you very far defiantly not in a hurry. It should be double that or more depending on turbo health and mods. Is the intake and turbo all factory? What's the air filter look like? Done the red tube delete or cranked down the wastegate actuator rod yet? How's the turbo compressor wheel look, signs of dusting?

 

Data is attached. I am charting it in Google Sheets as I don't have Excel.
MGP max was 5.8
MAP max 18.9
EBP Max 35.6
What should these readings be?

Stock truck except larger exhaust an I think it may have an old school super chip.
Air filter is new. No red tube mod and I have not adjusted the waste gate actuator rod.
Turbo bearings and wheel replaced a couple thousand miles ago. My son did the work so I'll ask him if he noticed anything funky while he was in it. He's pretty capable so chances are he did a better job than I would.
It is possible that this problem has been around for a while as I only put a couple hundred miles a month on it.

 

I've got a pretty good idea what your problem is, at least one of them. I scrolled that entire log and according to the PCM you never went WOT. I think the highest I saw was 56-58%, that's leaving a lot on the table. Your EBP does seem a little high but that hangs on what you have for an exhaust too. I'd start with pulling your floor mat and checking that nothing is blocking the skinny pedal from going to the floor. You'd be surprised how many times it's really that simple. If no G.I. Joes or LEGO's hiding under there then the APP assy. or connector is the next logical suspect.

 

Put a fuel pressue gauge at the end of a hose long enough to place it so you can read it when you stand on the accelorator. I'll bet it drops off under load and that is a fuel volume issue. It only shows up when fuel demand is high and the fuel supply system cannot keep up with demand. IMO this is a very common issue that is overlooked on these trucks. Mine would drop off to 20 PSI just accelorating around the block, let alone trying to pull a load with it. Did some things to the truck that eliminated the flow issues and it's pulled like a bull elephant ever since.

 

I wish you were right! But I think I was just being gentle. I had done a scan a few minutes earlier where I think I truly pushed it all the way to the floor. Data is attached.
That time APP was 74% wick h I believe is WOT, correct?

 

I was thinking the same thing except how would I get over 2700 psi from my ICP reading if it was fuel starved?
I did what you suggest recently but I returned the borrowed pressure gage to my buddy.
I'll get it back or buy my own if needed.

 

I'm want to say the 74% is still a little on the low side. I always view it as a voltage so not real sure how that shakes out on the % scale, but 4.2v is WOT on mine.

 

If the pedal isn't the problem then finding out why you are only able to build 6# of boost would be my priority. The exhaust looks slightly restricted but it's not glaring, do you have a CAT on the truck? You might want to check the tube that goes from the intake to the MAP sensor. It could have a leak or crack causing a bad reading or they also can fill up with oil from the CCV system. If it's not reading properly the PCM could be trimming the fuel because there isn't sufficient boost to justify more. It's already been suggested to look close for up pipe and manifold leaks. Here's a dumb question but how's the brakes? Checked and greased the caliper slide pins recently? They are very prone to drying out and hanging up, causing the brakes to drag. Oh final question, what's you elevation? Your BARO says you're sea level but you MAP says you're 3000'. So either one of them is wrong or the engine is actually pulling a vacuum on the intake which shouldn't happen. That would suggest an obstruction in the breather/air filter.

 

I think he has the pedal down - I was looking at some of my past data files, and I see alot more boost at even 60% APP.

If the fuel pressure checks out, could this be a boost leak? MAP is much lower than typical with that EBP. The high pressure oil side seems happy.





With the turbo being rebuilt, and not much driving since, maybe one of the hoses is not sealing - recommend a boost leak check.

 

@BWST have you done the red tube delete and wastegate adjustment on your rig? I know back before I made those changes my e99 wouldn't build boost worth a damn. I don't think it was as bad as what we're seeing here, but I'm wanting to say 10-12 was tops but that took some flogging and the 12 was not seen very often. That's been more been more than a few years ago and I don't even know how many mods/upgrades ago. (Yes I've got PMS, but it's totally not a problem or anything.)