E67 REP during VE tuning

[1LEMan]

A couple issues during VE tuning on this E67 427.

1. I have set MAF fail to 0 hz and P101,102,103 to MIL on first error. I go for a ride and get my LTFT's. When I return and let it coast to idle it goes into REP mode and barely idles. I have to clear the only code P106 to get it to run again to get back home. I was getting a P068 error but I change that to no error reported. I think I am answering my own question: raise the airflow delta diagnostics???

2. The first time I logged LTFT's they were only -5% or so. I'm logging .4 to .7 kPa vs 2000 to 4000 RPM. I multiply % into the manifold open VE table ( I can confirm the % changed correctly) and calculate coefficients. I flash and warm up fully again and go for another ride. Now the LTFT are +10% in a bunch of areas....and probably correlate to zones. I've not seen this happen before. Usually I get the correction I put in the VE table.DonsRegalModified427_R14.hpt

Appreciate any insight.

[GHuggins]

Research rich after flash and how to correct it. With that big of an engine change - I assume built engine because I don't know of a 427 that came with an E67 controller plus you named the tune "modified" - you're going to have to dial a lot of tables in. Basically wait 20 minutes before checking for fuel errors after flashing hot and dial your itt table in for the lean hot restart - will save you a motor down the road too as this will cause PE to lean out the hotter temps it sees... You can kill the p0106 or dial in the diagnostics - you'll need to dial it back in after tuning in your airflow tables.

[1LEMan]

Thanks Greg. I was thinking Intake temp was only 10 minutes. I went for a long drive - about 25 minutes and looks pretty good now. see screen shot. Couple spots to tweak. Yes a pretty healthy camshaft.

The airflow delta was my REP problem like I thought.

LTFT.JPG

[Alvin]

A couple issues during VE tuning on this E67 427.

1. I have set MAF fail to 0 hz and P101,102,103 to MIL on first error. I go for a ride and get my LTFT's. When I return and let it coast to idle it goes into REP mode and barely idles. I have to clear the only code P106 to get it to run again to get back home. I was getting a P068 error but I change that to no error reported. I think I am answering my own question: raise the airflow delta diagnostics???

2. The first time I logged LTFT's they were only -5% or so. I'm logging .4 to .7 kPa vs 2000 to 4000 RPM. I multiply % into the manifold open VE table ( I can confirm the % changed correctly) and calculate coefficients. I flash and warm up fully again and go for another ride. Now the LTFT are +10% in a bunch of areas....and probably correlate to zones. I've not seen this happen before. Usually I get the correction I put in the VE table.DonsRegalModified427_R14.hpt

Appreciate any insight.

You need to raise the airflow diagnostics for both. You can max them out.. It's ok. Turning the code off is not the right solution.

The rich after reflash is due to "injector offset vs injector tip temp" Most OS's don't have this or it is zeroed out. Something is messed up with the injector tip temp calculation after a reflash and this offset screws up the fueling for about 10 minutes or so. It is completely fine to just zero this offset table out. Again I'd say more than not have this table zeroed from factory.

[1LEMan]

Thank you Alvin. Yes I recall zeroing this out on other GM tunes I did before. It's been a while and I forgot that setting. This particular file has values in it starting at 130 deg. It's zero'd out now!

[GHuggins]

Zeroing it out will make it worse, but what do I know right.... Those values add fuel and you were already 10% lean, so 0ing it out will make it worse. I've never once seen one zeroed out from factory unless it's an older cal. I recommend dialing the itt (injector tip temp) in as previously recommended All depends on your fueling corrections needed.

[1LEMan]

Greg,
I can't seem to get the VE coefficients to stick in the idle area. I've tried about three times now. What am I missing?DonsRegalModified427_R16.hptR16.hpl
Thanks again,
JamesR16.JPG

[GHuggins]

It's how it calculates the zones out. Try to target something in the -3 to -4 range. I recommend using Cringer's VE assistant if you haven't been introduced to it yet... It will show you the projected afterwords trims - watch the vids on how to use it - I also did a write up in the editor section under adding zones or something like that for it - you can edit the VVE as many times as you like without having to fire the car up and get a rough idea on your outcomes.

[1LEMan]

It's how it calculates the zones out. Try to target something in the -3 to -4 range. I recommend using Cringer's VE assistant if you haven't been introduced to it yet... It will show you the projected afterwords trims - watch the vids on how to use it - I also did a write up in the editor section under adding zones or something like that for it - you can edit the VVE as many times as you like without having to fire the car up and get a rough idea on your outcomes.

Yep. That's what I needed. Thank you!

[Alvin]

Zeroing it out will make it worse, but what do I know right.... Those values add fuel and you were already 10% lean, so 0ing it out will make it worse. I've never once seen one zeroed out from factory unless it's an older cal. I recommend dialing the itt (injector tip temp) in as previously recommended All depends on your fueling corrections needed.

Every GEN 4 Truck file I opened this morning had zeroed out ITT tables. Checked all the way up to 2013.. The last model year of them.



And it's likely 10% lean because he's been pulling fuel after a reflash because the ITT tables have been leading him astray.


It works like this..

He flashes.
ITT calculation is messed up from the reflash, takes 10 min to get back to normal. In the mean time the offset is effecting low PW areas especially.. causing a rich idle/decel area especially.
He makes a tune edit to correct this

Later he logs it with the ITT settled and it shows lean.


If you intend to keep ITT You need to give it a solid 10-15 minutes after a reflash before logging. This might not be possible with really big injectors as the thing will be pig rich with huge injectors and a bit of extra injector offset.

[blindsquirrel]

2009 Silverado 1GCHK53K99F111387 LY6 6.0 E38 (12587269 33.9lb).hpt
2009 Express 1GBJG31K291176609 2500 4L80E (127lb E38)1470025278.hpt
2012 Silverado 1GC1KYEG1CF221580 E78 L96 (OS 12647731)(12613412).hpt
2017 Silverado 1GC4KZCG6HF205677 E78A L96 (OS 12677353)(12613412).hpt

[Alvin]

2009 Silverado 1GCHK53K99F111387 LY6 6.0 E38 (12587269 33.9lb).hpt
2009 Express 1GBJG31K291176609 2500 4L80E (127lb E38)1470025278.hpt
2012 Silverado 1GC1KYEG1CF221580 E78 L96 (OS 12647731)(12613412).hpt
2017 Silverado 1GC4KZCG6HF205677 E78A L96 (OS 12677353)(12613412).hpt

I'll see you and raise you this.. All untouched from repository.


1409866091.hpt
1294874446.hpt
1436583546.hpt
1432087972 (1).hpt

[blindsquirrel]

Oh, not disputing that none of them are all zeroes. Just that not all of them are.

[Alvin]

I never said all of them were.

[GHuggins]

I actually found a few in my files that were zeroed 7's to 12's. Not all of them were and the 13's were really hit and miss, but I did find a lot of truck chassis files 0ed. Not sure how I overlooked it. BUT you are correct that there were some from factory 0ed.

In this case to make the OP's not lean - I would still add where it's going lean - if it's not lean from taking fuel out after flashing, which the way he worded it, it's lean after flashing only? That's if I understood it correctly...

Odd that all of the emission stuff was really hitting in 7 and they zeroed them out even though it would throw off hot engine fueling.

[blindsquirrel]

Every GEN 4 Truck file I opened this morning had zeroed out ITT tables. Checked all the way up to 2013.. The last model year of them.

Sorry if I read that wrong.

[Alvin]

I actually found a few in my files that were zeroed 7's to 12's. Not all of them were and the 13's were really hit and miss, but I did find a lot of truck chassis files 0ed. Not sure how I overlooked it. BUT you are correct that there were some from factory 0ed.

Here is a '13 I just read out.. 0ed out.

read.hpt




If the car is being tuned and the tuner does not understand ITT when the tune is finished it will be lean especially in low PW areas like idle and decel.


If the car has 1000cc or 2000cc injectors that injector tip temp will totally screw you. It will be VERY VERY rich while ITT is messed up. If you compensate for that it will be VERY VERY lean when it comes out of it.

[Alvin]

Sorry if I read that wrong.

When most are zeroed... its easy to see how when I open a handful of files they are all zeroed. statistically.

Plenty of instances in this thread where I say "most, many, quite a few, etc"

[RobZL1]

In my opinion, I think there are other things in the background that correlate to the ITT table that we don't see. In OS's that came with zeroed ITT, I imagine there are other tables we don't see that play nicely with the zeroes. In the OS's that have values in the ITT table, I imagine those need to be tuned in order to continue to play nice with the unseen background logic instead of zeroing them out. That's just my guess. I know my experience with ITT suggests if the ITT table has values in it from the factory, you need to tune those values.

[1LEMan]

In my opinion, I think there are other things in the background that correlate to the ITT table that we don't see. In OS's that came with zeroed ITT, I imagine there are other tables we don't see that play nicely with the zeroes. In the OS's that have values in the ITT table, I imagine those need to be tuned in order to continue to play nice with the unseen background logic instead of zeroing them out. That's just my guess. I know my experience with ITT suggests if the ITT table has values in it from the factory, you need to tune those values.

And no manual or source code to figure out crap like you mention.... but I understand that these controllers were meant for production vehicles to start in -30 to 130 deg F -300 to 13000 ft and not your average hot rod.