OFT Dead Spot 1000-1700
 

This is something I've only just recently noticed, and as a result, was able to duplicate. I flashed back to E85 for the spring on V2.063 EL (stock header).

Between 1000rpm to roughly 1500-1700 their appears to be a black hole when you get into OL fueling.

If I short shift into 2nd and the rpm's drop into that threshold and I squeeze the throttle into OL the car just sort of stops accelerating and just sort of hesitates and literally decelerates despite being at 100% WOT. If I back the throttle back into CL range it starts accelerating again.

Almost feels like a black whole..sort of funny actually. I'm almost never usually in that range but was turning around in a parking lot the other day in 2nd gear and the car almost just stopped. I can reproduce it in any gear, as long as I'm in that RPM range and get out of CL into OL fueling.

Anybod else ever seen this?

I'm also on the OFT e85 EL tune, however I haven't noticed this. Post a datalog so we can see whats happening. If you're feeling it fall on its face then something is definitely wrong.

I don't remember this happening to me doing 2nd gear pulls from 1.5k RPM.

http://www.datazap.me/u/joneze93tsi/...7-8-9-10-12-13


I don't see anything out of the ordinary other than lack of ignition advance.

It just flops

interesting mine does the same exact thing.....i cant WOT until the rpm is past 2k....if i do, the car struggles to accelerate...other than that, pulls really strong. im on the stage one 93 UEL map

Maybe I just need to spend more time in OL in that rpm range and let it adapt further. Truth be told, it's so rare that I'm even in that range that it's probably spent almost no time there.

I don't see how that would help, there's no "adapting" going on. To me the fact that the ignition timing drops to 0 degrees and then stays there is more than likely the cause. However, I have no idea why without seeing the tune.

http://columbusht.com/Stg%202%20EL%2...01C_V2.063.bin


That's the file I current have loaded. Been at least 1500 miles since I've flashed it runs exceptionally well outside of this small issue, which really may not rear itself again for a 3 months lol.

Nothing in the tune shows any reason why that should be happening. It's quite odd. It clearly stays at 0 degrees advance though.

¯\_(ツ)_/¯

Suspect it load limit.

op dude can you log engine load instead of vvt cam angles.

@joneze93tsi can yoy log engine load instead of vvt cam angles, you might be hitting a load limit from memory think it something like 1.35. at lower rpm

do you have stock intake ?

I can do another one shortly.

I have the "shiv" modified snorkel and a drop-in filter, that's in intake wise.

http://www.datazap.me/u/joneze93tsi/...1-2-3-6-8-9-10

I went in and out of this condition several times, with load logged as well.

Ignition advance seems to disappear beyond 1.3 load, I think you are onto something..:w00t:

I was able to replicate this as well. I'm on Stage 2 UEL, pretty much OTS tune other than adjusting the MAF for my intake.

I am pretty sure mine does not do this , however i have made heaps of changes to my E85 tune to suit our guaranteed 85% ethanol fuel.

As the oft guys make their tune run on a wide variation of ethanol percentage they appear to have artificially bumped up the values in the Open loop area of the maf scaling. Maf valus are an input to the load calculation the ecu does, as i have rescaled my maf my load values are less and i dont seem to trigger these limits.

you are running afr of 11.25 which is rich limit of sensor so it may be richer , the value in tables is about 12.3 .

I have not changed the load limits in my tune, but i suspect rescaling maf has eliminated the issue for me, although i rarly go 100% throttle at such low rpm.

Traditionally large throttle openings at low RPM cause engines to knock. It may be some built in knock prevention that is exasperated by the tune. If you drive a manual you really shouldn't be going WOT below 2k rpm, that said if it bothers you I would say @steve99 is on to it and will help figure out what is going on.

I do remember reading other threads about lack of power at low rpm with a cut snorkel in particular. Perhaps the snorkel mod negatively effects air velocity into the air box at such a low RPM.

I'm not really concerned with it, as this is the first time in 18K miles I've ever ran into it.
Just thought I'd see if it was a common thing/discuss it further.

I take my last posts back. Stage 2 EL e85, went WOT in 2nd gear and my logs show drops in timing down anywhere from 1 to 5deg around 1500rpm. Intake is stock. Only mods are the tune, e85, and muffler delete.

I've never ran in to this before as I've never gone WOT that low. Even for my datalog runs I am in 2nd or 3rd at 2k RPM or higher. I think you can ignore this as under normal driving you'd never be WOT that low, and racing you'd be between 5-7k RPM anyway.

No log below 2k RPM which is what you're looking for, but my car otherwise runs perfect. Below is a 2nd gear pull on the EL tune if you'd like to compare timing.

http://datazap.me/u/slowbaru/iam-2nd...9&zoom=281-480

Tried this yesterday 1000 rpm full throttle up in 5th up hill grade no problems slowly climbed to 3000 no dead spots, my e85 tune has a few mods however.

Just going to inject this here:

http://www.ft86club.com/forums/showthread.php?t=80260

WOT issues before 2k, theres another thread i made before that too

same for me, no issues even down that low and in a condition that I would never see on the street or anyplace else.

5th is too high of a gear. Try in 2nd, you'll likely feel it more if its there. I tried in 3rd and 4th and did not notice the timing dip because of the taller gears. Dropping down to 2nd I immediately felt it.

yep tried it in 1,2,3,4,5,6 no dead spot.

timing will drop that normal due load increase check out the base timing B table in any tune or stock, light load more advance high load less advance

these guys ere talking about complete loss of power.

My car completely falls on its face if I give it >50% throttle below 2000 rpm; it just bogs out and won't accelerate at all. This is on the 91 octane ESC tune with a modified snorkel. I'll try to find the log I captured it on but from what I remember when it happened, my AFR pegged rich and load shot up to something ridiculous like >4.0 g/rev.

Is there anyone with this problem who doesn't have a modified snorkel? It seems like that, besides an OFT tune, is a common thread for people experiencing this.

Subbed

I have seen some combinations of ethanol formulations and cars run quite rich at low RPM full load. I suspect it may be caused by some combination of header design, MAF turbulance and lower Ethanol %. All that you need to do to fix it is adjust the primary fuel table. The OTS AFR values will be in the mid-12:1 range down like this:
http://i85.photobucket.com/albums/k4...0table%201.jpg

I fixed the issue by just tweaking it as such:
http://i85.photobucket.com/albums/k4...0table%202.jpg

You can confirm by just datalogging a few low rpm/high gear pulls. The nice thing is that the engine will happily accept a pretty wide range of AFR at that low engine speed. Anything result from an actual 12.5:1 to 13.5:1 will work fine.

I think more likely because the load limits have been removed on C series roms. This never happens on other calibrations in OTS tunes because they're limited to about 0.9g/rev with stock load limits and thus reasonable AFR and positive ign adv.

I would bet good money all the people with this issue have C series roms.

These tables aren't defined in my 700G rom using the OTS v2.xx XMLs. How would I go about getting them added in?

go to wayno post on e85 petrol tunes link in his signiture , grab his definition for 700G rom and you will be sorted

they did not max out the load limits on the g roms so you should be fine anyway.

if you use wayno tune and good maf scaling you will be even better

In my thread

Thank you all for the quick replies.

I don't suffer from the dead spot mentioned in this thread but after flashing back to the stock ROM recently I noticed taking off from a stop was much easier and I was looking into why when I noticed my definitions were missing the above.

Hi guys! Got the same problem...

2015 Scion FR-S - Stock tune with EcuTek P0420 removal.

Injen intake (got it for really cheap for testing, no hate here please)
OEM headers with gutted cat
Nameless FP/OP combo

If I WOT in between 1200-1800 rpm the engine really want to die out. Because of the de-cat and the intake, not-that-nice noise are going out from the exhaust and intake.

For the one who have the problem, check your MAF g/s or voltage data. Just a quick look at mine:

I'm not saying it's the problem but it could be intake resonance that make the MAF freak out from the modified snorkel/aftermarket intake. My logs must be worst because of the "great design" of the Injen intake.

EDIT: Just for fun, before I'll do the logging for the intake rescalling I've try the @Shiv@Openflash fuel map and It really soften the problem! Thanks ;)

You shouldn't really do that in any gears other than 1st, maybe 2nd. It's not ideal to labour the engine at low revs.

Seeing those MAF readings I do wonder if load limits are an issue as well as the intake.

Moral for the story, don't go WOT at low RPM ;)

Yeah I know it's not the perfect condiion, but in some situation it could happen...

You know the kind of "oh ok got just the time to pass" you floor it in low RPM range and the car just die -_-

Never had problem of 'car just die' with WOT@low rpms (on still stock car). Slow acceleration - yes, but 'die'? Of course i judge only by by hearing, that engine sounds normally from 1600 and up, but never saw any problems using low rpms (starting these rpms) at least while steady cruising at whichever the gear in. 1500 has noticeably different sound in upper gears, hence i always downshift, if required to go lower, but above - seems just fine to me.

If Injen intake is unscaled your likely running high LTFT (like you would with most other aftermarket intakes)

log the fuel trims and AFR when you go wot at low rpm its likely going rearly rich

once you fix the maf scaling the problem will likely go away

I know that I've got to recale my maf, from now my LTFT is like at -5% but I got to take cupple of other ride. But from what I see, it's "physical" air resonance that cause the maf the freak out as you can see on my log.

But well I could be wrong I'm begening to play with my ECU :)

is the injen intake the one that moves the maf sensor very close to throttle body ? , if so your likely correct its caused by resonance/turbulance