6.0 goes dead lean in boost. Log and file attached.

[vr4508]

1999 Chevy 2500
6.0 with 317's
BTR stg1 cam
decaped injectors. I tested and flowed them on a real bench. 58 psi they flowed between 662 and 665 cc's. Converted to pounds at 6#s for a gallon of fuel my math is 65 pounds an hour.
I'm running a return style boost ref'd fuel system.
The pump is a demon 525 pump.
I'm running a 2 bar OS but am using a 3 bar sensor. I did this to get a bit more granularity and I don't anticipate running more then 14-ish pounds anyway.
Turbo is a 78-75 with a 3-4 psi spring in the gate untill I sort this out.
I am running strait open loop SD. (or at least I'm trying to)

The log and the tune are attached.

The problem is the truck will tip into boost and be pretty rich and then suddenly go dead lean to the point the KR goes crazy and it will actually pop out the intake.
In the log its around 2.01.862
I do not have the ability to log the afr unfortunately but the wideband on the dyno pegs super quick.

I have ran a fuel flow test. Hot wire the pump and run the return into a 5 gallon jug. With only batt voltage of around 12 it fills a 5 gallon jug in just over 30 seconds. This is in line with the 525 pump info I can find and certainly good enough for the 125 kpa I'm running into the problem at. That also eliminates the fuel bucket starving as well.
I pulled the injectors and re-flowed them as a sanity check and the results are the same.

I've been over the tune a bunch and can't find anything for sure. Is there anything you guys see I did wrong? I have done a few of these and never had an issue like this before.
Thanx guys.

[ryan_axberg]

I would zero out the spark modifier tables except the iat modifier. And on that one you could multiply by .5. I would set minumum map enable on power enrichment to 80 kpa, put the power enrichment eq ratio to like 1.18. boost enrichment map enable to 105 kpa, and for low boost like your running you could put a eq ratio of 1.25 in the lower boost range and richen it up as you go higher in boost. You also have stft enabled in open loop. Your ve table takes a big change at 95 kpa and higher, it should be a smooth table.

[ryan_axberg]

I would zero out the spark modifier tables except the iat modifier. And on that one you could multiply by .5. I would set minumum map enable on power enrichment to 80 kpa, put the power enrichment eq ratio to like 1.18. boost enrichment map enable to 105 kpa, and for low boost like your running you could put a eq ratio of 1.25 in the lower boost range and richen it up as you go higher in boost. You also have stft enabled in open loop. Your ve table takes a big change at 95 kpa and higher, it should be a smooth table. You should also figure out how to log your wideband, it makes everything so much easier

[Lakegoat]

I would make sure that you have something like BR7EF plugs gapped at .025. Next, look at the 3D ve table since you are tuning in SD. That might be some of the problem also.

[vr4508]

The plugs are tr6's. Bit warmer but gapped tight.
So I tried a bunch of stuff today. I tried completely starting over. I returned the truck to stock by writing entire the original file I pulled. I replaced tyhe injectors and the map sensor with stock parts. The only difference at this point was the little cam. I pulled the gate spring as well. i drove the truck around and all is good. Albeit boring.
I reinstalled the 3 bar map
I installed a set of bosch 210's just because I had them and to rule out the decapps.
I installed about a 3-4 pound gate spring.
I then reopened the stock file, applied the 2 bar OS. saved to a new name, closed and reopened the new file, wrote entire and then started a new tune. The tune attached is what I did.
After all that the truck does the same thing. I believe I zero'd out what you suggested minus the iat stuff.
I ran a fuel pressure gauge to both rails, both read the same and never fell under load. Again, this pump fills a 5 gallon bucket out the reg return in less then a minute at 58PSI. I just can't imagine delivery is a problem.
I'm running out of things I know to do. Other then scrap it and go stand alone. lol

[cabelas90]

The plugs are tr6's. Bit warmer but gapped tight.
So I tried a bunch of stuff today. I tried completely starting over. I returned the truck to stock by writing entire the original file I pulled. I replaced tyhe injectors and the map sensor with stock parts. The only difference at this point was the little cam. I pulled the gate spring as well. i drove the truck around and all is good. Albeit boring.
I reinstalled the 3 bar map
I installed a set of bosch 210's just because I had them and to rule out the decapps.
I installed about a 3-4 pound gate spring.
I then reopened the stock file, applied the 2 bar OS. saved to a new name, closed and reopened the new file, wrote entire and then started a new tune. The tune attached is what I did.
After all that the truck does the same thing. I believe I zero'd out what you suggested minus the iat stuff.
I ran a fuel pressure gauge to both rails, both read the same and never fell under load. Again, this pump fills a 5 gallon bucket out the reg return in less then a minute at 58PSI. I just can't imagine delivery is a problem.
I'm running out of things I know to do. Other then scrap it and go stand alone. lol

Could It be a trq mng setting?Untitled3.png

[kaik]

We are going to find out!! LOL I'm 90% sure I've tried all that before, but we are going to again.
Thanx
The other thing i don't get is the log does not show any type of drop in pw or dc. So unless the logger does not show something for some reason, like some "behind the scenes" clip or max-limit, ECU output does not seem to show any issue.
The thing just goes too lean too fast to be a fuel supply problem. It goes from 11-1 to 18-1 and popping in about a second. And thats at 1-2 pounds of boost. Drifting lean i could get but the fuel pressure gauge never falls, the pump flows 5 gallons in 30 seconds at batt voltage at 58 psi, and the rails themselves are pretty big. The engine would have to be useing ALOT of fuel to effect afr that much at such a low fuel demand. This thing is probably only making 150HP at that point. The other day I pulled the relay and started the truck just to make sure the gauge would actually fall and was not just stuck. The truck ran at idle for 5 minutes on just the residual fuel in the rail and feed lines. So the rails hold a significant amount of fuel.
Also the other trucks I've done I've always just copied and pasted the stock ve up to the 105 row and then the 105 row to max KPA row, add30% to the max row and interpolate between them. That has always given me a VE table in boost that if anything was too rich by about a point. This one just makes no sense.

[cabelas90]

Im just wondering if that 350lbs is causing it to pull fuel? Let me Know what you find!

[Davem3261]

Does it have any knock sensor codes? A bad knock sensor or harness will cause it to pull timing as soon as you get into boost. Also your are commanding a 10.5 afr in boost and your ve table ramps up the fuel alot as soon as you are in boost.

[vr4508]

No knk codes. New sensors and a new knk harness. The knk sensors seem to work just fine. Soon as it goes stupid lean they ride to the rescue.
Yeah I'm commanding stupid rich and getting basically the opposite once it starts to come into boost. Once I have the fuel under control I'll shoot for 11.5-12-ish. By commanding as rich as it is, I figured it may give me a bit more time to collect data before it hits the wall.
The drastic VE table rise is just to rule out a table thats too lean. The table didn't start off this way, I built toward this disaster to try and rule out a tune problem. I'm telling the ECU to drown this thing and instead get an engine that is so lean it shuts off. Or the engine is shut off and thats why it shows lean. Either way.....
Thanx for looking. Any input is appreciated.
I have a few more things to try as soon as it stops snowing.

[vr4508]

So I tried maxing the tq settings to no avail.
I went back to 3 bar OS just so I could use the default 3 bar map sensor settings in the tune. Also to no change. Truck still goes full lean and pegs the wideband then pops through the intake.
Fuel pressure gauge still doesn't wiggle and duty cycle is so low I cant see it being the cause.
This is the current tune I'm trying. Anyone see anything goofy?

[kevin87turbot]

Does it have the original fuel line, or have you replaced it? The PCM is commanding A LOT of fuel. The first datalog shows the target AF is 10.5:1...and has nearly 45% DC at 3900 rpm. Do you have a datalog with the new injectors?

[vr4508]

Thanx for the question.
It has the original fuel lines. The feed is 3/8 and the return is 5/16.
I am running the "Faster llc"n fuel rails for a TBSS intake. They are these guys....https://www.ebay.com/itm/2007-2014-T...wAAOSw32lYsbod. I have used them a bunch before and never had an issue.

I run the 3/8" to -8 adapter fittings that everyone uses to connect the two.
I do not have a log yet with the new injectors as its been snowing a bunch. Its finally stopped and started to thaw, but snow and turbo 2wd truck is oil and water. Monday looks to be the day to try a new flogg.

[Rocko350]

whats the baro update setting set to. I cant open your files. Not on my normal computer. set it to 8000
chris

[vr4508]

I looked through the tune and did not find any "baro update" to speak of. Even used the tune navigator to search. Nothing found. Maybe a different name in this ECU or OS? In any event, Thanx for any and all insight.
I hope to have a log tomorrow. Snow finally went away.

[Lone_mfkn_wolf]

hows it going with that tune? im having the same issue on a p01 ecm 3bar. lean tip in only on WOT, seems if i roll in to it like under load and create boost the afr stays in the 11s but as soon as i stomp it goes extremely lean.

[Rocko350]

i reread your inital post. I missed it the first few times. The baro update becomes a fixxed issue whn updating to the custom os's offered . Using a 2 bar os with a 3 bar sensor is wrong. A 2 bar sensor is producing 2.5v at 5 lbs where a 3 bar would produce 2.5v at 11 lbs. The crossover where vacuum becomes boost is at a different voltage range too. The kpa values in the table your using are really voltage ad counts from the sensor. What does KOEO map read? I bet its at 130 kpa.. change senros or the os.

Chris

[vr4508]

Never did get it sorted out. I know for fact its a tune file though. I laid a Micro and drop on harness on it and although it leaves the trans in 2nd, it works and does not go lean. Just pulls strait to gate. So its either a software problem or a ecu issue at this point. I'm tempted to just ditch the factory ecu altogether and just hang an aftermarket ecu on this thing and drive away smiling but I'm just not ready to give up yet.

I've never heard of a problem with the map vs ecu thing as long as the map characteristics are correct in the tune. With the 2 bar map with the 3 bar map with the correct map values it koeo around 104 kpa or so. It idles around 60 kpa which seems correct. Am I wrong there?

[Lakegoat]

If that is a GM 3 bar map sensor, I believe that the offset is a negative number. Look up the part number and check. Could be an easy fix---except you will have to clean up the tune.

[V8_Kind_Of_Guy]

I am having an identical issue, p01 ecu, 3 bar gm map sensor, whipple, 1050x injectors.

my issue is just before boost though, at about 60/65kpa (Im also at 5000 feet so 82 kpa is the same as the ea level guys at 100 kpa). Cyl airmass goes from .42g to .29g and spark jumps up. 17 to 30 deg.

I have a different thread going on because I didnt see this one. Any more help with this issue?