PE enabled, but not activating (0411 8322)

[woody80z28]

One of the first things I did to tune my 8.1 was to enable PE by changing the delay timer from 60sec to 0sec and TPS enable from 90 to 70%.

I also noticed it didn't seem to do much, so I put a wideband in it. Well, at WOT it's showing me 14.8-15.1 on the wideband. I can see the TPS% at 99 in the log.

I am logging a couple more degrees spark (as I added), and the fan control I added is working - so I know the tune and flash process is functional.

There's gotta be something I'm missing here. Any idea what I could be doing wrong? BIN attached.

[steveo]

does your datastream output a flag for power enrichment active? is it being set?

[Fast355]

One of the first things I did to tune my 8.1 was to enable PE by changing the delay timer from 60sec to 0sec and TPS enable from 90 to 70%.

I also noticed it didn't seem to do much, so I put a wideband in it. Well, at WOT it's showing me 14.8-15.1 on the wideband. I can see the TPS% at 99 in the log.

I am logging a couple more degrees spark (as I added), and the fan control I added is working - so I know the tune and flash process is functional.

There's gotta be something I'm missing here. Any idea what I could be doing wrong? BIN attached.

Set enable KPA to 55 and enable torque down to about 70%.

[woody80z28]

No flag, I'm logging with TunerPro via bluetooth. Limited PIDs.

MAP PE is at 55 already. I don't see anything in this XDF about "enable torque." There's enable TPS, and I've already changed that from 90 to 70. And my TPS is reading 99 in the log.

I have my PE EQ ratio set at the stock 1.240 for B3618 PE modified based on RPM
B3617 PE coolant temp and B3641 intake temp are both full of 0s, but it says they are added, not multiplied. So I don't think they would be causing an issue.

[woody80z28]

So I opened up HPTuners and a random 8.1 file I had downloaded and I do see the PE enable torque % is set at 100. MAP is set at 55, MAP hysteresis is 6% and torque hysteresis is 15%. Neither of those torque settings are visible in TunerPro. They are labeled 2414 and 2413 in HPT, but PE delay is 2415 in HPT and it's labeled B3608 in TPRT.

[woody80z28]

Bump. Anyone know a way to convert a .HPT file to .BIN perhaps?

[In-Tech]

I changed Power Enrich Enable Torque Threshold to 0% like in the Camaro/Transam. Pretty sure I got the checksums all correct.


CONSTANTS:


Fuel Parameters

Power Enrich Enable MAP 55 Kpa
Power Enrich Enable Torque Threshold 100 % Torq.

[woody80z28]

I changed Power Enrich Enable Torque Threshold to 0% like in the Camaro/Transam. Pretty sure I got the checksums all correct.


CONSTANTS:


Fuel Parameters

Power Enrich Enable MAP 55 Kpa
Power Enrich Enable Torque Threshold 100 % Torq.

Thank you! I'll flash this tomorrow. May I ask, how did you do it?

[In-Tech]

Hello,
I opened the .bin file in TunerCat, saved it as a .cal(only option for saving) Then changed the value(Power Enrich Enable Torque Threshold) and re-saved with new name. I opened both .cal files in Hex Workshop and wrote down all the changes and line number in the .cal. Then searched the .bin in Hex Workshop and found the addresses of all the changes and altered them to match. Then saved the new .bin file.
It takes a while and even though it was only one value change, a lot of other things get changed. John's(TunerCat) software isn't free but is well worth it to me. If you open up the text file I added, you can see all the stuff available in his software. I'm not advertising just pointing out how much work goes into software, the free stuff and the pay stuff. Back in the eprom days it was quite a bit simpler, find the byte you wanted to change, alter it and correct the 16 bit checksum and go. Shoot, when I started(early 90's) there was no software and we were working straight in hex and had to burn a chip every time. Then affordable emulators came out(I had an xtronics pocketrom) and you could disable the checksum and hunt and peck in the area where it should be based on what you had disassembled(which is a shit ton of work).
-Carl

[woody80z28]

That is pretty awesome. I'm glad there are people out there smarter than me. Haha.
I've been tuning obd1 for about 10 years, and totally reliant on the work of others in $a1 and $od. I'm just now learning a little bit about hex while working on an obd2 adx for my bluetooth adapter.

[woody80z28]

Hmmmmmm... I just tested out the BIN, and with the PE EQ ratio set for 1.18, the wideband was reading just over 16:1! That's supposed to be about 12.5:1. Stock was 1.240, so there's no way it could be backwards right? Cause 1.18 lambda is about 16:1...

But the good news is, it does appear to be entering PE. Wideband was about 14.7ish at moderate throttle, then moved to 16:1 at WOT.

[Fast355]

Hmmmmmm... I just tested out the BIN, and with the PE EQ ratio set for 1.18, the wideband was reading just over 16:1! That's supposed to be about 12.5:1. Stock was 1.240, so there's no way it could be backwards right? Cause 1.18 lambda is about 16:1...

But the good news is, it does appear to be entering PE. Wideband was about 14.7ish at moderate throttle, then moved to 16:1 at WOT.

Sounds like low fuel pressure, unmetered air leak or a dirty MAF to me or some poor WOT tuning masked by closed loop at WOT.

[woody80z28]

Maybe the factory tuning its really bad? Truck is stock, with a drop in filter and smooth intake tube. I've read something about a MAF reading incorrectly if the tube isn't the same diameter. Maybe corrugated vs smooth also makes a difference?

[LRT]

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[woody80z28]

Interesting nugget about PE on an 8.1... I've been making comparison pulls up a mountainside headed out of town as a "dyno" but they are only taking about 20sec to go from 2000-5000 in 4th gear at WOT. I can't think of any place steeper to try and prolong that. Maybe I could try 5th.

I just flashed a PCM set to fail the MAF instantly and run on SD. I want to get that in today and try it if it stops snowing.

If it really is open loop activating and not PE, I recall a table for open loop EQ that can probably be purposed to work like PE.

I'd like to try your bin as well. Can you give a hint of what's done to it? Just in case it's "not defined" in the xdf.

Thanks

[LRT]

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[woody80z28]

Gotcha. Thanks. Looks like I was editing my post when you added yours. That's the exact kind of thing I was envisioning to get around a PE issue.

[woody80z28]

Great success!

I modified the LRT bin to also disable the MAF and mistakenly flashed the non-modified one. AFR was low 14s. So I looked at it and realized what happened, flashed a MAFless copy and AFRs were in the low 12s. My ~19-20sec "dyno" pull only took 16sec! That's a definite improvement.

So I know I need to do some MAF scaling. Very excited though...cause now I know I can make changes and see results.

Thanks to everyone who helped out. I would not have figured this out on my own.

[LRT]

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[woody80z28]

Thank you. All input is appreciated.

We're "essential" so even though NY is mostly closed, I gotta go to work. But we're on 4 days right now cause orders are slow. And today is beautiful! So I just got back from a drive.

Tires: yes, I went from stock 245s to 265s. What's the TOS? EDit: nvm. Trans output shaft speed.

Fans: That old bin is from when I was setting up my fans. My operating temp was only hitting mid 160s, so I set them there just to be sure the harness worked. It's set to 192 now. I actually replaced the tstat with a 180, thinking the previous owner may have put a 160 in, but it didn't change the operating temp. Warmer days now have put my operating temp in the mid 170s, but my gauge is always about 185...even when the datalog and my handheld read 160. Strange. I don't see an added bypass anywhere.

Spark: I made those the same to simplify tuning like my obd1 Beretta. Maybe that's not ideal.

I just logged another bin where I reactivated the MAF after adding 10%to the g/sec chart. That put my wideband in the mid 14s at WOT. I'll make the fan changes, etc and try yours, too. Edit: Looks like you added more than 10%. Which is needed.

I'm working with Kur4o to get a decent solution to datalog with TunerPro and the obdlink. We're adding KR logging, but that showing 1.5deg the whole time, so something needs adjusting. That whole deal has been a challenge, too.

Going to flash and test it now.

[woody80z28]

Hmmm. I tried that bin out and it gave an MIL (P1336 Crankshaft Position System Variation). It was noticeably less responsive. But it had to have entered PE (13.4 at WOT) with the open loop table set at stoich up top.

I put the last tune in just to be sure it wasn't a sensor problem and the MIL went away and the throttle response came back.

[LRT]

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[kur4o]

I am almost sure that the case relearn data is stored at the eeprom region of the bin 4000-8000 area, which can be overwritten only in clone mode. Under normal programming it shouldn`t be updated. Maybe the error is caused by some other settings that affect this DTC.

LRT you have lots experience with the ls1 code. It is completely off topic but have you managed to figure out the routine that sends data via the ALDL bus on the ls1 pcm. I am trying to find it and make a hack that will enable the pcm to stream custom data via aldl for logging essential data. I looked at a lot of dissasemblies but I am not even close to figuring this out.

Confirming the PE mode can be done by looking at the stoich target the pcm use. If it is stuck at 14.7 all the time, than there is indeed no PE enabled.

[woody80z28]

Quick lunch break reply, I'll come back later.

I did a full clone flash with your bin, because I also added kur4o's aldl patch. I can try it again without the patch if you'd like.

[kur4o]

For the patch to work only OS+cal data is needed.

edit:
Once the OS is flashed with the patch, than only CALdata writes are needed.

So if you want to try the LRT bin, there is no need to repatch since the OS is the same and you need only caldata write.
Clone is used only if you have a junkyard pcm and you want to make a mirror image of it, so all the learned stuff and vin is the same between the 2 pcms.

[woody80z28]

Ok. Your one post in the other thread mentioned full flash and another said OS, so I just did a clone to be sure. I have two PCMs I'm swapping and hadn't patched the other one yet... that's how that all worked out the way it did. But I can clone back to my native BIN and then write the OS from your patch and caldata from there on out.

[LRT]

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[kur4o]

The big tuning companies are missing some basic stuff in their definitions. They never put enough time to figure more than just the basics. Tons of parameters are not defined yet. As per the example for the PE on.

If I managed to find the aldl datastream code, high speed logging one of these PCMs will real fun.

Could it be a table for PE to be set at 14.7 and even it enters PE the AFr is at stoich all the time.



But I can clone back to my native BIN and then write the OS from your patch and caldata from there on out.

You can clone it back with the patch applied. Than caldata write only from there.

It is really unclear for a lot of people how this clone OS and caldata work. There definitely needs to be some guide written about that.

[LRT]

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[woody80z28]

Hopefully we can figure this out together. It'd be nice to help discover information rather than just consume it.

[LRT]

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[woody80z28]

Please try the Bin attached below. It was edited using the publically available XDF - no experimental parameters changed yet. The MAF Sensor calibration was adjusted based on your feedback.

If PE remains disabled, then the WOT AFRs should hopefully now be in the 14.1 to 14.6 range (Stoichiometry) - if so, then the MAF curve is reasonably close to being accurate for the specific air intake system on your vehicle.

If the WOT AFRs are in the low 12 range, then PE has actually enabled (not likely).

As before, please leave the MAF enabled, and closely monitor your Wide Band Oxygen Sensor readings.

Flashed the cal only after cloning back to my own BIN. But something is still weird. No MIL, but the idle AFR was in the high 11s low 12s; Part throttle was low 14s and WOT was 16-17 before I let off...didn't give it a full pull.

I wish I had better data, but the bluetooth logging is being problematic.

EDIT: Took another drive to record a log and found there is actually PE or something going on. There's a 1sec delay or so, but after the initial 17:1 lean spike, it drops to 13.5ish at WOT.

[LRT]

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[woody80z28]

I have the wideband output tied into the PCM for logging, but can't get it to work right. The numbers I'm referencing come from peeks at the gauge while driving.

And the gauge had another face for lambda, so I'm pretty sure it will read 14.7 as stoich, even with the E10 crap we have at there pump.

[LRT]

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[woody80z28]

Yup, peeking at the actual gauge is how I'm getting numbers.

I'll see if I can change the digital readout to lambda. I don't recall that in the instructions. The gauge face has 1lambda at the same spot on the outer led sweep as 14.7afr.

I've tuned my Beretta as "14.7 stoich" according to the wideband even though it also runs E10...and the actual afr is probably in the low 14s. I don't think the wideband knows or cares.

[LRT]

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[LRT]

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[woody80z28]

Hmmm. Similar results, even with a different calibration on the MAF. WOT spikes lean and then comes down to mid 13s. Low 12:1 idle initially, but corrects itself to 14.7 with STFT pulling a ton of fuel out.

I'm new to the MAF and its effect on fueling. All my OBD1 stuff has been speed density. Thinking about disabling it again to do some VE table refinement and reduce variables. As I recall, it ran a fair amount better that way, too. The STFT and LTFT are reporting correctly in the log, so I'm thinking that may be where my time is best spent in the immediate future.

Thoughts?

[In-Tech]

Sounds like low fuel pressure, unmetered air leak or a dirty MAF to me or some poor WOT tuning masked by closed loop at WOT.

I'd like to point this above right on post out. The MAF meter is probably almost 20 years old. 90% of the new/rebuilt ones are sometimes worse than the dirty/coated one you take off. There is no reason EVER to have to alter the transfer function of that MAF in the calibration. Are we smarter than GM on this transfer function? That type enclosed MAF with screens is dead nuts and reliable till it gets dirty or typical age ozone and dust coated. The only ones you can buy that seem to be correct are the AC-Delco and Delphi NEW maf's, not the rebuilt junk at NAPA, Oreilly's, Autozone, etc. You said you have a stock engine so unless you made changes to alter the VE(exhaust, cam, porting, etc), your VE table should be pretty right on too. Best thing to do to start is turn off VE and get it to run correctly on just the stock MAF settings.
I am not talking about cartridge MAF's and how they are critical to inlet ducting and any change in that can cause a lot of grief.

LRT has been very kind to help you, chasing failing or just bad equipment doesn't help anyone.

Good luck,
-Carl

[Fast355]

I'd like to point this above right on post out. The MAF meter is probably almost 20 years old. 90% of the new/rebuilt ones are sometimes worse than the dirty/coated one you take off. There is no reason EVER to have to alter the transfer function of that MAF in the calibration. Are we smarter than GM on this transfer function? That type enclosed MAF with screens is dead nuts and reliable till it gets dirty or typical age ozone and dust coated. The only ones you can buy that seem to be correct are the AC-Delco and Delphi NEW maf's, not the rebuilt junk at NAPA, Oreilly's, Autozone, etc. You said you have a stock engine so unless you made changes to alter the VE(exhaust, cam, porting, etc), your VE table should be pretty right on too. Best thing to do to start is turn off VE and get it to run correctly on just the stock MAF settings.
I am not talking about cartridge MAF's and how they are critical to inlet ducting and any change in that can cause a lot of grief.

LRT has been very kind to help you, chasing failing or just bad equipment doesn't help anyone.

Good luck,
-Carl

If that is true...
Why does GM have different MAF transfer tables for the very same MAF in different applications? The LT1s are different F-car vs Corvette LT1 vs Corvette LT4. The Vortec trucks are different than the Vortec vans. The 350 vans have 2 different MAF tables depending on which airbox they used too. The 4.8/5.3/6.0L trucks are different than a LS6 Corvette too. I think GM calibrates the MAF transfer for the airbox they used with the MAF. For example, ALL 2002 V8 gas powered vans had the same MAF and airbox. The 305, 350 and 8.1 all used the same MAF transfer except around idle.

I know my Express van ran like crap on a 2002 Express van MAF table using the 97 airbox and ducting. When I swapped to the later ducting and airbox it was still off. I had a good clean OEM MAF and a new smaller body Delco MAF that they sell to replace the larger LT1/Vortec MAF. Same results with both. Camshaft seems to really effect fueling up to about 30-50 gms/sec. First thing I do is disable the MAF and tune the VE. Then I disable the VE and tune the MAF. Even on stock setups they are usually pretty far off the mark.

[woody80z28]

I have some MAF cleaner, I'll give it a good cleaning.

I would have thought the tube style MAF would be accurate regardless of intake configuration, but I read otherwise. Like I said, I'm new to MAF stuff. If you're certain that doesn't matter...I'll believe you.

Mods consist of an intake tube and a muffler, so I would agree the VE should be pretty close. The fuel trims change quite a bit now, but maybe that's all influence from MAF.

[Fast355]

I have some MAF cleaner, I'll give it a good cleaning.

I would have thought the tube style MAF would be accurate regardless of intake configuration, but I read otherwise. Like I said, I'm new to MAF stuff. If you're certain that doesn't matter...I'll believe you.

Mods consist of an intake tube and a muffler, so I would agree the VE should be pretty close. The fuel trims change quite a bit now, but maybe that's all influence from MAF.

In my experience the intake tube will throw the calibration out substantially on the MAF. I have a go to LS truck MAF calibration for the 07+ Airaid MIT that I like to use with earlier E-Fan conversions. I used my sisters low mileage bone stock 03 5.3 Tahoe with the MIT and E-fans as the only mods to create the MAF table years ago. Only reason it was even moded was the mechanical fan exploded and destroyed the shroud and intake tube.

I will say the MAFs on GM are far less picky than the cartridge MAF on Nissan and Infiniti. Even if you leave the OEM MAF in the OEM housing. Only change the intake hoses for freer flowing silicone hoses and the car will run rich. Luckily I combined the intake hoses with headers, high flow exhaust and a custom 2.5" dual exhaust that have an effect of leaning the car out.

[In-Tech]

I am not talking about the garbage 3 wire maf in the early stuff or the 3 wire used in the 0411 express.

[In-Tech]

The 07+ 5 wire is not the same animal either. Continue on, I'll be quiet.

[Fast355]

The 07+ 5 wire is not the same animal either. Continue on, I'll be quiet.

I would like to hear more on what you have to say.

Just have seen variations in that same 85mm 5 wire MAF you are talking about in various GM applications.

As I mentioned a 2003 Tahoe 5.3 has a vastly different MAF transfer table than a 2004 LS6 Corvette. The Corvette MAF table is my go to calibration for startup for LS swaps with the MAF connected to the throttle body via a short straight intake tube. If you run the stock truck MAF table I have seen MAF codes with that setup and the fueling is way off. The problem is compunded when people put a short silicone hose off the throttle body and a cone filter on the MAF.

[In-Tech]

Of course the tube can change some of the dynamics but not much with that 5 wire maf as long as the distance is similar. You can't hook that maf(or any other for that matter) straight to the throttle body and expect it to work, the pulses, angle of the blade, etc will screw any idea of that thing working correctly.

[In-Tech]

I would like to hear more on what you have to say.

Just have seen variations in that same 85mm 5 wire MAF you are talking about in various GM applications.

As I mentioned a 2003 Tahoe 5.3 has a vastly different MAF transfer table than a 2004 LS6 Corvette. The Corvette MAF table is my go to calibration for startup for LS swaps with the MAF connected to the throttle body via a short straight intake tube. If you run the stock truck MAF table I have seen MAF codes with that setup and the fueling is way off. The problem is compunded when people put a short silicone hose off the throttle body and a cone filter on the MAF.

Yes, you are correct. The Corvette and the GTO each have different transfer functions but completely different intake tube tracts. We are still dealing with an '01 truck aren't we? That's all I am getting at. As soon as I look at a tune that others have been in. My first look is at the MAF table and if others have been in there I just throw it away and start from stock. The ford guys used to have no choice cuz theirs was friggin horrible, any change and it was fubar so it's normally ford guys who jump right into the maf table first.
:popcorn: :happy:

[Fast355]

Yes, you are correct. The Corvette and the GTO each have different transfer functions but completely different intake tube tracts. We are still dealing with an '01 truck aren't we? That's all I am getting at. As soon as I look at a tune that others have been in. My first look is at the MAF table and if others have been in there I just throw it away and start from stock. The ford guys used to have no choice cuz theirs was friggin horrible, any change and it was fubar so it's normally ford guys who jump right into the maf table first.
:popcorn: :happy:

01 truck with a non-stock intake tract.

[woody80z28]

01 truck with a non-stock intake tract.
Yup. This and this. Not exotic, but not stock. The tube is 4in diameter, and the MAF is about 3.5 if I remember correctly.

https://i.imgur.com/TTM8Z3M.jpg
https://i.imgur.com/yo5kXjX.jpg

[woody80z28]

Ok, I cleaned the MAF really well and double checked for unmetered air leaks. (No leaks and the MAF looked pretty damn clean, but it did change my AFR a bit after the cleaning.) However, what I really noticed was the angle of the tube right after the MAF. It has a much more noticeable bend than you really see while installed in the truck. I wouldn't be surprised if that skews the sensor readings.
https://i.imgur.com/yoThTca.jpg
The intake was an ebay special for "2500HD" but it turns out it's for 4.8/5.3/6.0 and I had to modify it a bit to fit 8.1. Unfortunately, I already tossed the stock stuff so I can't do a sanity check on the sensor.

What I did see though, was the idle was high 11s until the LTFT hit 80 and STFT hit 95. So that's pulling out 25% to hit 14.7 right? Steady state low throttle at 2000ish rpm the LTFT was about 90-92. WOT was 100 LTFT and 13.0-13.2 AFR. So math-wise it seems like the calibration is non-linear.

So I'm going to disable the MAF, take a log and make sure my VE tables are pretty good with a historygram. Once I'm happy with the VE tables, I'm thinking of adding 6% to the stock MAF curve, re-enabling and taking a look at the LTFT historygram again.

Then, will I be able to use LTFT in a newly built historygram of RPM vs g/sec to tune in the MAF? Since I can't get the wideband to report to the datastream, I can't do an AFR error calculation like I keep seeing in how-tos for MAF scaling.

[woody80z28]

Made a huge datalog at varying RPM with the MAF disabled (attached). LTFTs are much closer with the MAF disabled. +/-2% for most of it...up to +5-8% at the top of the log. I adjusted the VE table and I'll log & retune another couple times.

Then I can work on the MAF. LTFT with the a history table for g/sec sound like a solid plan?

[Rocko350]

im not at a computer where I can open the tune files in the thread. OP did you leave the screen in the MAF? I may have missed that. I hope you did. You will need to rerun fuel trim adjustments to the MAF curve. Fats355 is dead nuts on. Your going to need to rerun your fuel trim learns on your MAF curve. As far as PE enrichment, I tuned an 8.1 in a g3500 drw bus of all things and found the enrichment ramp in rate was set stupid low. Its like a AFR adder. It slowly adds fuel to the desired PE AFR. But from the discussion id say you have a 2 fold issue right now. Too slow of enrichment rate and the maf curve is off. Disable PE and rerun your maf learns and then lets get back to PE.