PE Mode Enablers

[The Alchemist]

Hi guys,
I'm tuning a cammed LSA engine at the moment and am having issues with PE mode and when/how its enabled. I have the throttle area enabler set very low <15% and MAP threshold at say 80kpa. I can hold the engine at say 95kpa under load and its stays in closed loop. Its not until I get to about 120kpa that the commanded fuel jumps into PE mode.
I have also noticed this in non supercharged E38 Holden V8's so its not just a LSA thing. Its almost like there's other enablers in the firmware that we just don't have access to.
Its clearly NOT just map threshold and throttle area dependant.
Have other people struck this before and do you have any ideas as to what the other conditions may be to enable PE mode?
Thanks,
Mike

[joecar]

Hi Mike, can you post your .ctz file, (or can you post the stock file)...?

[The Alchemist]

LSA Holden VF original

[The Alchemist]

is anyone still on this forum apart from Joe ? :)

[joecar]

Mike, so you're seeing PE not enable even tho all the "visible" enablers allow it to enabled...? And only on this vehicle/type...?


edit: fixed spelling/typos.

[The Alchemist]

correct, the commanded AFR stays at 14.7:1 yet I'm over the kpa enablers for MAP and for TPS, say 110kpa and 30% throttle. I've seen this with other N/A L98's LS3's etc. IF you bury your boot hard enough it transitions into PE mode of course.... I just think there must be other enablers such as "TPS rate of change" enablers in the tables..... I've been aware of this issue for years and just put up with it so to speak, but when tuning a boosted LSA and I'm still running 14.7:1 at 120KPA I sort of panicked a bit :)

[Highlander]

The problem is that on Gen IV 30% is 30% AREA... not throttle percentage... 9% is about 35% throttle blade opening. So you need to set it lower and use the kpa B0157 to control at what specific load you want it to trigger.

[The Alchemist]

excellant thanks !!!

[joecar]

Mike, how did that work out, tell us your results.

[johnsZ06]

http://giant.gfycat.com/MiserableImportantKingsnake.gif

[ACCLR8N]

I am having an issue with this as well, seeing 130 kPa and still commanding 1.000. I have had B0157 set to 55 kPa. Looks like I will have to be much more aggressive going after B0156 throttle area if 35% TP is only 9% area. I didn't know the ratio of throttle area to position was so drastic. In addition I am also going to lower B0167 timer from 10 to 2. Lots of snow outside, don't know when we can get the buggy back out.

E67 variable cam Ecotec adding a turbo.

[ACCLR8N]

Following Swingtan's tutorial on the E38 VVT, lowering B0156 from 95% down to 4% got it to behave correctly. Quite a drastic change.

[Highlander]

Because the table references throttle Area and not throttle rotation....

4% throttle area = 29% throttle rotation

22023

[Boost]

I am having the same issue with a Gen3. Although my absolute throttle PID seems to be reading super low, wonder if it's an issue with the aftermarket throttle body. My AFR stays 14.x : 1 while flooring it, scary lean and no horsepower

wideband log attached:

23666

[Boost]

Well my issue is fixed. I had to super desensitize several settings to get PE mode to finally kick in at all - gained like 200 horsepower (seriously)
Sorry about the slight change of topic since mine is a Gen3 but I've been working with PE mode enablers for weeks
:cheers: good stuff

[joecar]

Well my issue is fixed. I had to super desensitize several settings to get PE mode to finally kick in at all - gained like 200 horsepower (seriously)
Sorry about the slight change of topic since mine is a Gen3 but I've been working with PE mode enablers for weeks
:cheers: good stuffHi,

What specifically did you do...?

[Boost]

sorry Joe I've been busy still tuning the car and FINALLY making great progress

to be completely honest there were a number of issues that complicated and confused the situation

some of those are incorrect throttle body, exhaust leaks and bad tune

that being said to answer your question it was the PE Map Threshold and Normal PE Mode Enable that I messed with

sorry that I was being dumb about this the entire time but I had a vacuum leak and also I finally realized that if I look at Commanded AFR I can see when it "switches" in the log - whether the fuel system keeps up or not

So basically I made it go into PE very very easily to "try to diagnose that it actually can" but most of the time I was in open loop with multiple DTCs set so my findings probably aren't very helpful to anyone

Moral of the story double check all your mechanical integrity and monitor data thoroughly and accurately before tuning!

:hihi::lookaround::ermm:

[joecar]

No worries... stuff like that happens to me many times, lol. Glad you got it sorted out :cheers:

:)

[Boost]

No worries... stuff like that happens to me many times, lol. Glad you got it sorted out :cheers:

:)

Thanks Joe, I hope all is well and I sincerely appreciate all your help through the years.

Here are some accurate Dragy rips from this weekend, we definitely have an honest 400 rwhp now.

The 30-70 time is respectable according to this list: http://car-videos.net/performance/speed.asp?Speed1=30&Speed2=70
23736

And the 1/8 mile is very satisfactory to me considering I bogged it off 1500 RPM with a full tank and a passenger and then it spun tire for 2 seconds straight at the top of 1st, and into and through most of 2nd.
23735

[joecar]

Thanks.

Good job :cheers: (that would be like low/mid 12 second quarter).

Another benefit of 400 rwhp is the ability to steer using the throttle :banana:

What app are you using to measure acceleration and speed (shown in your pic above)...?

[Boost]

Thanks.

Good job :cheers: (that would be like low/mid 12 second quarter).

Another benefit of 400 rwhp is the ability to steer using the throttle :banana:

What app are you using to measure acceleration and speed (shown in your pic above)...?

I am using a Dragy which is popular and accurate - some of the best $150 I spent. Comes with a free app you download on the phone and a nice sticky magnetic pad for the dash (or wherever). Very compact with good battery life, back to back real life track testing shows .1 sec accuracy.

Thanks again yes both of our cheapy / oldie Chevys are a BLAST - local feared underdogs and truly daily driven (only transportation for kids / school / work hahaha!)

It has gotten a little bit faster still, and a full drag pack is going on this Friday the 2nd to try to realize my goal of 7.7 @ 94 on motor 1/8 mile.

Then I can hopefully spray it into 6.9 @ 100 with 150 shot

I am just so thankful and ecstatic for these humble and modest gains, literally lived in the $3300 Camaro not too long ago...

Truck is salvage title and was purchased for $2800.

:thumb_yello::thankyou2::good:

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23755

[joecar]

The collection of small reliable gains makes quickness.

[Boost]

... a full drag pack is going on this Friday the 2nd to try to realize my goal of 7.7 @ 94 on motor 1/8 mile.


https://youtu.be/xpuuXcI94ng

Didn't quite get the 94 Mph but got 92+ and extremely pleased and thankful

https://youtu.be/xpuuXcI94ng