yobabiesdaddy2001

iTrader: (20)

How do I disable my PE, so I can tune my STFT's. The write up that I read on it, says that I go to Engine General> Fuel control> PE: and then under pe enable put in the number 680. My HP tuners does not a place to put the numeral. It only has HOt Tps and Cold Tps, and then up under that it has temp tps box for a number in fairheit degrees? Is that the box?

RedHardSupra

iTrader: (1)

dont EVER disable PE!

Rhino79

iTrader: (7)

Don't disable it, just change the TPS enable % to 95% or so and do not go into PE when VE tuning.

MeentSS02

iTrader: (11)

Why not? I do it all the time...tune it like you drive it, right?

chrisj6

hey Len, just set the TPS% to 90 and the MAP enable to 90, you will be fine. You want the PE to come in so you dont blow anything up.

1320ft

iTrader: (3)

Hey, I am getting ready to do STFT tuning as well. The setting you are looking for is under PE enable>MAP. You will see the MAP setting is a 15kPa stock. You want to change that to 640 (not sure why it needs to be that high to disable, maybe someone else would like to chime in ) Anyway thats what is says to do in the write-up I am following. Also I am using HPtuners.

ZL1Killa

iTrader: (17)

.... why turn it off? why not leave the car in CL like it is.. dial in your LTFT's and be happy and don't stare at the STFT's ....

why? my car runs fine tuning the LTFT's.... and tuning my WOT to what I desire via MAF table.


?? if you ask me i think you are tuning things u don't need to mess with, not that its a bad thing, but its a waste of time

yobabiesdaddy2001

iTrader: (20)

LOL! Man Chris I was anxious to get out thier and finsh tuning my ve, and got tired of waiting on a response from someone. I disabled the pe went on another log session and after about 15 min........ BOOOOM! The dam thing locked up.

yobabiesdaddy2001

iTrader: (20)

Ok SIke!!
Although I did get tired of waiting for some help. I went ahead and read some more and did a little problem solving and eventually came to the conlclusion if I cant find a way to disable it , I will just set The TPS% vs Rpm to 100% from 0 to 4000rpm's and it worked.
I knew you guys would get around to help me out I just couldnt wait!
Redhardsupra and Chrisj6

MeentSS02

iTrader: (11)

You didn't listen...you can tune your VE table with PE still enabled. And you should.

yobabiesdaddy2001

iTrader: (20)

Oh I listend Ment, we just have two many people saying to many different things. I chose to listen to the guy who is in my area.
That way if really tare somthing up, I want have to buy a plane ticket to beat him down.





Just playing chris

RedHardSupra

iTrader: (1)

i dont know where the myth of turning off PE as a good idea started, but it's plain wrong.

BEN's (EFILive) or AFR%Error (HPT) have the correction factor defined as (AFRcommanded-AFRactual)/AFRcommanded. AFRcommanded is whatever falls out of OLFA/PE/BoostEnrichment (in custom OS')
the only reason to tune with disabled PE is if for some reason we were not able to measure AFRcommanded, and instead we could only use stoich. this way (stoich-14.7)/stoich would work only without any acceleration fuel enrichment, because it would require a constant stoich, instead of variable AFRcommanded. but, with all the different GM PCM's floating around, I am yet to see one which doesn't have the AFRcommanded PID, so there's no reason not to use it.

there are cases/methods/approaches where it would help to turn PE off, however, they're rare, and require fairly deep understanding of all the inner workings of the PCM. if you're a newbie that is just folowing directions without real understanding what's going on, leave it alone.

short version: dont disable PE unless you really really know what you're doing, otherwise you might be trying really hard to blow up your engine.

brad8266

iTrader: (23)

Yeah you dont want to go 90% throttle and have the PCM stay in closed loop, it can possibly cause damage.

The way to do it safely is to leave the PE set to what it was, and when you enter PE you can log your actual sensor read AFR and compare it as a percentage against your commanded AFR and adjust the MAF and VE tables in those ranges according to the percentages you need.

Example. the PCM commands 13.0 AFR @ WOT and you go WOT and read 12.8 AFR on the wideband. You need to decrease the amount of fuel amount, so you decrease the values in the proper MAF and VE cells by multipling the values in the cells by 98.46%. (12.8/13.0=.9846). This will lower the values and then you try going WOT and you should read 13.0 AFR on the wideband.

I wouldnt worry too much about STFT's though, focus on dialing in LTFT's real good.

RedHardSupra

iTrader: (1)

closed loop does NOT equal targeting stoich ratio. in our cars the two occur together, but technically speaking, they're two completely separate concepts.
if your car was designed to work with a wideband from the get-go (like a 1.8t VW) it continuously corrects fueling (that's the proper use of term Closed Loop). since widebands can monitor the full AFR spectrum, and computer can adjust for it real time, there's never a need to ignore inputs--that's the reason why we temporarly ignore NB O2s when targeting non-stoich AFR's.

brad8266

iTrader: (23)

yeah i know that, i was just saying that if he disables PE and goes WOT he is asking for trouble.

RedHardSupra

iTrader: (1)

i know, i was just explaining semantics. not really relevant in our cars, but i think it's important to get the concepts right from the start, and if he's not sure if to turn PE on or off, he's definitely starting

yobabiesdaddy2001

iTrader: (20)

Thanks for the help guys but I never turned the PE off I just raised the TPS% in the lower rpm's so PE wouldnt come by accident when I got close to the 4000rpm mark.

Redhardsupra, Ws6snakeater has a write up that tells you how to tune narrow band starting with the LTFT's and then on to the stft's. You probaly seen it. He says that you should start at 1200 rpm and gradually pulse your way up to 4000rpm while trying to hit every load cell. I tried its hard! I dont really like the method. I eventually figured another way to hit as many cells as I could and then go back and hand smoothed.

Can anyone send me a link on how to tune (dial) in the Maf?
Thanks guys!

MeentSS02

iTrader: (11)

You still don't seem to understand the concept here...PE doesn't come on by accident...it comes on for a reason. It isn't like you are gonna be cruising at 4000 RPMs anyways, so why would you want it to necessarily command stoich there? Leave PE at the stock settings (I've got mine even more sensitive), and tune from there. The commanded AFR will change, and the calcs will go off of that if/when it needs to.

I know you aren't tuning with a wideband, but you can still filter the histogram results by the commanded AFR. Set the filter so that it only allows values above a commanded AFR of 14.5-ish or so to show up in the histogram.

yobabiesdaddy2001

iTrader: (20)

I should have use the word "accident",

yobabiesdaddy2001

iTrader: (20)

can you explain "filtering".