Lean transition into PE and lean spot during WOT

[07GTS]

HPT just informed me that it is not possible to add to my 07 E38, because the setting doesn't exist in mine. I never had a lean spike issue that I couldn't get rid of so I assume that if its not in the calibration, it doesn't have the negative effect.

i havnt seen it pop into my tune either and i don't have the issue so i assume will stay good, 2007 e38 also

[Tre-Cool]

well i've experienced the problem in a holden 07 ecu with 100lb injectors. so it will be interesting to see if it shows up in both software products for that tune.

[realcanuk]

I guess it depends on actual version number. Ive used ID850s and now ID1000s in mine and never had anything I couldn't tune out.


Unfortunately no such table in the code for your operating system so we are unable to add it, sorry.

That's what HPT said regarding my ECU.

[10_SS]

I got Desoot last night, my OS 12637084 -> 1250235 thanks HPT Sounds like I wont see a difference though, never noticed it before since I already had the 2bar upgrade which sounds like it never had the problem.

[GHuggins]

2 bar upgrade had the problem too - that was the OS I tested it on - fixed it Actually the car in my signature that we added nitrous too...

[10_SS]

2 bar upgrade had the problem too - that was the OS I tested it on - fixed it Actually the car in my signature that we added nitrous too...

awesome! What the heck didn't I see it? Ahh, must be my fine tuning skills. j/k Just curious at this point. I still go lean at 29.0 AFR above 4000rpm at WOT tip in, goes rich below 4000rpm at tip in, but I dont have knock and no bucking or delay so Im ok with it. Was hoping this would change that.

Over 1000hp (crank) on a stock bottom end alum block LS3 am I reading that right?


BTW, at about 15mins on my log I got that freeze you were talking about.. lol It happened right after entering WOT which was strange then unfoze right while leaving WOT Which was even weirder.. like too much changing too fast and caused the lockup, OR one value being too high makes it freeze up.. it unfroze but wow that was weird I thought the Wideband went bad for a minute.
FREEZE.PNG

[GHuggins]

It's supposedly on the E67's too - I don't recall ever seeing this problem on them - in fact I remember seeing a couple of them go overly rich if anything, but doesn't mean that the problem wasn't there and I just tuned around it another way?

Well, it's disabled from the factory on most e67s

[reubone]

how do you get desoot mode activated?

[Rawr256]

SOLVED!

Engine -> Fuel -> General. Injector Control, Enrich Desoot Mode

Set to disabled.

You sir are my hero! I was just going to chalk this up as something to live with and hope it never causes a potential issue down the road. Curious why something like this would be active and need to basically re-enable with each WOT hit.

[Tre-Cool]

I got Desoot last night, my OS 12637084 -> 1250235 thanks HPT Sounds like I wont see a difference though, never noticed it before since I already had the 2bar upgrade which sounds like it never had the problem.

Excellent to see. my friends car noses over hard, rpm drops down to what i expect this to be the cause of. It's literally about 1.5 seconds after going into pe mode. Hoping to have this fixed before hitting the track next week. his is a 2010 camaro with the same OS.

Despite the nose dive from 5500rpm to 2850rpm in 1st gear the car still managed to run a 10.05@ 146mph

[Atomic]

So if your OS doesnt have the option or feature how do you fix this issue? I am working on an E38 and the de-soot mode is not part of the OS according to the engineers at HPT :/ So much for an easy fix.

[Rawr256]

So if your OS doesnt have the option or feature how do you fix this issue? I am working on an E38 and the de-soot mode is not part of the OS according to the engineers at HPT :/ So much for an easy fix.

Have any logs of when yours does it? On mine like Niemer's it was literally at 2 seconds after hitting PE. Is yours doing it at 2 or is it lean on tip in? If you don't have Desoot enable/disable switch I would think it's Transient fueling related.

[10_SS]

Excellent to see. my friends car noses over hard, rpm drops down to what i expect this to be the cause of. It's literally about 1.5 seconds after going into pe mode. Hoping to have this fixed before hitting the track next week. his is a 2010 camaro with the same OS.

Despite the nose dive from 5500rpm to 2850rpm in 1st gear the car still managed to run a 10.05@ 146mph

WTF... the problem must be magnified with much bigger injectors? Not sure why you would see it and I wouldn't if we have same OS. You want my complete file incase Desoot doesnt fix? Ok sure have it if you have unlimited license you can try it for free.

[Tre-Cool]

WTF... the problem must be magnified with much bigger injectors? Not sure why you would see it and I wouldn't if we have same OS. You want my complete file incase Desoot doesnt fix? Ok sure have it if you have unlimited license you can try it for free.

Appreciated, but i primarily tune with efilive & don't want to use up credit's on my hpt cable just for this switch just yet.

My theory is the bigger the injectors, the bigger the issue. I think the ecu must either drop/hold to a certain msec PW. Since this car has the 2200c bosch cng style injectors even at max boost/power it's only running about 8.6msec pulsewidth.

If i don't get the updated cal from the efi guys in the next few days, I should be able to tune around it by disabling PE all together and using the open loop enrichment tables (which i already use anyway, since it runs full time open loop).

[reubone]

Mine appears in beta 3.5 only

[Atomic]

Have any logs of when yours does it? On mine like Niemer's it was literally at 2 seconds after hitting PE. Is yours doing it at 2 or is it lean on tip in? If you don't have Desoot enable/disable switch I would think it's Transient fueling related.

I will post some logs when I get home, but it is 2 seconds after PE starts, long after transient stuff should have gone away.

[Atomic]

Ok here is a good log showing the issue. It only happens under heavy throttle, moderate throttle, even though in PE, does not do it near as bad.

PE_LeanSpike_2sec.hpl

Look at timing marks 4:35, 5:08, 5:58, 6:21, and 6:41. This is a 2007 E38 silverado with a turbo and scaled injectors. Walbro 450 fuel pump.

[Rawr256]

Ok here is a good log showing the issue. It only happens under heavy throttle, moderate throttle, even though in PE, does not do it near as bad.

PE_LeanSpike_2sec.hpl

Look at timing marks 4:35, 5:08, 5:58, 6:21, and 6:41. This is a 2007 E38 silverado with a turbo and scaled injectors. Walbro 450 fuel pump.

It doesn't look it does it the first few times that you go into PE but does it afterwards. I would almost think it's something involved with the PE delay or another enrichment? The 2:21 and 3:38 mark looks clean, the ones around the 4 - 6 min marks seem really bad and the later ones don't seem as bad. Nothing in the fuel system controls at all? You check the beta on your tune to see if it's on there? Between all of the different hits it almost seems like there really isn't enough change to show a reason for it being different. I'm stumped on that.

[Atomic]

Yea thats what I mean when on easy entrys into PE like half throttle or so it does not do it near as bad, but the later hits at more power clearly do it. All the fuel stuff is set correctly and the pressure holds steady and yes I have the beta.

It is just so consistent with the 2 second delay I thought for sure the "de-soot" mode was the fix/cause, but the OS I am working with doesnt have that it seems. Can you overwrite the E38s to a later E38 OS like you can the gen3 computers? Seems like a good option at this point and deal with the VIN situation separately.

[sillycon]

In doing my own digging on PE-entry related issues, I have come across some folks claiming that there are certain time-related PE settings which supposedly are available/used within the ECU (particularly with trucks) but which are not accessible via HPT. I haven't been able to independently validate such claims, however, so I don't know how much truth there is -- but it may be worth investigating just for sanity's sake.