Help AFR want change???

[Speedjunkie99]

Well for starters I dont know much about the car other than the mods I have done to it which include. Long Tube Headers, Cold Air Intake and a ported and polished throttle body. Its a 99 Transam with a A4 transmission 3.23 gears. I have tuned my VE table and have my LTFT between -5 and 0 with no knock. I have a NGK wideband hooked up and data logging the car goes from 16:1 at idle and normal driving conditions to 9:1 at wide open throttle the throttle response is horrible. I am going to attach a scan and my tune please help because no matter what I do adjusting the PE table or adding fuel in the VE table does it help. I even tryed setting my Stoich AFR to 12.5 but it still didnt efect it??? HELP I dont wanna burn up my car by running to lean.

[blownbluez06]

If you're running 9.0:1 at WOT, you certainly aren't going to burn it up from running lean. Wash out your cylinders from running rich maybe. You do know you have 2 VE tables correct? The values don't seem far from each other. From your 9.0 AFR and your being worried about running lean comment, I have to ask: you do know that means you're running rich and you need to reduce and not increase fuel right? That's 9 parts of air and 1 part fuel when you should be trying for 12.5-12.8 parts air to 1 part fuel.

How are you trying to tune the VE tables? SD mode? Explain how you're putting it in SD mode and which direction you're changing the #'s and with what result. For example, "I'm getting a 9.0 AFR and I'm taking the values in the VE table and increasing or decreasing them by X% with no changes."

[Bill@HPTuners]

Not sure why you are trying to tune the VE table at wot, maf is used for the airflow calcs over 4000 rpms in your calculation...

[Speedjunkie99]

Was just stating I have already tuned the VE table I have it correct. But at Idle speed and normal driving conditions I am at 16:1 AFR and at wide open I am at 9.0:1 AFR. I have adjusted the PE to try and compinsate for the over fueling at WOT but it want change. I also cant get the idle and normal driving conditions to change from 16:1. Any help would be appreciative? But I did tune the LTFT VE Table by logging several hundred miles and making the necessary corrections to get the 0 to -5 in all of my LTFT table...

[Bill@HPTuners]

You are at 9:1 afr at wot because you've setup your commanded afr to be in that range. There are alot of things that need to be fixed in the tune starting with stoich afr.

[Speedjunkie99]

I know i bought the car and it definately has issues. Tuning the VE table was the first thing I done but I havent changed anything to command 9.0 AFR at wide open throttle no shure where to begin fixing whatever someone done to this car.

[Cantalope Kid]

Well for starters I dont know much about the car other than the mods I have done to it which include. Long Tube Headers, Cold Air Intake and a ported and polished throttle body. Its a 99 Transam with a A4 transmission 3.23 gears. I have tuned my VE table and have my LTFT between -5 and 0 with no knock. I have a NGK wideband hooked up and data logging the car goes from 16:1 at idle and normal driving conditions to 9:1 at wide open throttle the throttle response is horrible. I am going to attach a scan and my tune please help because no matter what I do adjusting the PE table or adding fuel in the VE table does it help. I even tryed setting my Stoich AFR to 12.5 but it still didnt efect it??? HELP I dont wanna burn up my car by running to lean.

HOLD on their keyboard cowboy!

Do not change your stoich AFR to anything other than 14.7:1 or your stock setting unless you have a power added (blower, turbo, ect.) Basically leave it alone. Now you mentioned a 16:1 at idle...why? When you car starts up in OL it should be pretty rich...11's or 12's...then once warmed up and in CL it will ty to hit 14.7 (or whatever you put in stoich). 16:1 is very lean. NOT GOOD!

Now onto your WOT 9:1. This is WAY to rich my friend. Get WOT to 12.5-13.0'ish. No wonder you are suffering from a BOG like a sumabitch and I'm sure black smoke everywhere, with eyes burning.

Keep up these two scenarios above and your gonna kill your motor immediately.

You don't change your stoich AFR setting to get a 12.5 at WOT either. That is done in the PE section.


Fix:

Post up you vehicles information along with modifications.

Change your Stoich AFR back to 14.7
Change your PE settings to command a 12.5 AFR = 1.176 across the board
Now start over with your VE/MAF Tuning

IF you need a more basic explanation please ask. I am at work and can't post a click by click explanation right now. Please DO NOT guess. Ask questions!

Pm'ed you my cell phone number. I think when someone can talk you thru the steps it makes alot more sense.

[Speedjunkie99]

I know I just got the wideband in a hooked up and started data logging thats what scares the hell out of me is that it is ideling at 16:1 and under normal driving conditions its still at 16:1 and when i go WOT it goes to 9:1. I have no idea what someone has done to the car in the past just trying to get it write before I drive it anywhere. Thats why i started with VE tuning by unhooking the MAF and driving and adjusting over 100's of miles. But since my AFR is all messed up Im scared to pull it out of the driveway. Its one extreme to another. I am a newby to tuning but I knew there was something seriously wrong....

[Cantalope Kid]

Wife has my cell. Fubar on talking to you until I'm off work now.

Since I'm at work I can't see your attatched tune/log for adjustements or obvious WTF's! I will look asap when I get home. After 5:30PM CST. You honestly would be better off starting with a stock tune my friend. We can get you much further this way. Simply copy a stock tune for your year/model/tran. from the repository. DON'T AUTHORIZE the repository tune. Copy over the differences using the compare feature to your current tune and give it a new name before saving. DON'T save over your current tune...simply re-name it and go from there....you can either do this

OR

Get your stoich number changed back to 14.7 or whatever it should be stock. And re-log car at idle from a cold start. Let it idle up on its own. No throttle help or anything. ONLY at idle please.

I can give you a more in depth walk thru to get the PE (Power Enrichment) adjusted to 12.5 across the board. Need to actually see a frozen screen of the PE section to be certain I am pointing you in the right direction. I'll look around for it...This will allow you to have a base number (goal) to try to hit while adjusting your VE/MAF settings.

Where do you have you WB mounted? Are you logging AFR error? Do you have an understanding of the AFR error concept?

[Speedjunkie99]

The wideband is located in my Y pipe about 16 inches past the long tube headers at about a 10 degree angle. I will do a compare file and change everything back so we can start from scratch thanks again for all the help...

[Bill@HPTuners]

I know i bought the car and it definately has issues. Tuning the VE table was the first thing I done but I havent changed anything to command 9.0 AFR at wide open throttle no shure where to begin fixing whatever someone done to this car.

Changing stoich afr affects all of your fueling calcs including pe so yes you are commanding 9:1 afr or possibly richer.

[Speedjunkie99]

Ahh ok thanks Bill i done a compare file on a stock tune trans am same year and everything. I changed the stock AFR back to 14.7 and will begin tuning again from here. I still done understand why I am so lean at normal driving conditions. I know PE controls wide opne throttle but what controls normal driving is that the VE table?

[Speedjunkie99]

I am not logging AFR error not shure of the concept. I am a Newby and I am running my wideband threw my EGR wiring because i have the standard version.

[Cantalope Kid]

Well the value you put in your PE table (i.e. 1.167) is a function of STOICH AFR / COMMANDED AFR = 1.167

So its 14.7 AFR (STOICH) / 12.5 AFR (COMMANDED) = 1.167

If you change the STOICH which is typically a constant (never changes, atleast not naturally aspired) you will be changing the formula entirely which will really throw off your WOT AFR values since they are dependant on the COMMANDED AFR being a function of your STOICH AFR.

[Cantalope Kid]

Normal daily driving in closed loop is a mix of your VE/MAF tables. See your vehicle uses your MAF ALONG with your VE table up to 4k rpm's. They are constantly blending back/forth to keep things in check with your chosen stoich value. Your MAF is not able to keep up with transient (quick) changes in throttle response (i.e. quick blip of throttle or wot all of a sudden) on its own so it is constantly looking to your VE table for refrence of what should be happening. Consider your VE table the idiot proofing for your MAF. If it doesn't agree or just can't be calculated immediately by your MAF its calculated by checking against your VE table and its mixing time of what is/should be happening that is used.

Now anything over 4k your MAF is the ONLY table working regardless. Hence the wide open throttle refrence of MAF only. Your VE table is nill...void...not taken into consideration at this point unless...

your MAF is being taken out of the equation for some reason. For example...

IF you are going speed density. Speed density= no MAF.

[Cantalope Kid]

There are (2) ways that I know of to tune your cars VE/MAF settings...I learned 1 from not spending extra $'s for a wideband in the beggining and reading CPIG's guide (search) on here like it was the Coran which teachs you the LTFT's and STFT's way of tuning. It also has AFR error explanation I believe now. Later on when I sold a kidney and purchased a wideband I read until my bottom hurt from sitting on the thrown night after night trying to desperatly grasp the concept of AFR error. It made ALOT more sense when I had a wideband connected to the scanner to view. It simply does all the work for you in my opinion. Mind you ALL of what I learned in the beginning I later realized was and is covered not only in the stickies on here...but also in the HELP section of the editor if you dare read thru it all. There is alot of beginner info. there that everyone seems to skip...video's too!

In my humble opinion despite my weekend tuning/install business being named, 2 Tightwads Racing, I should have ponied up my spare $'s from the beginning and NEVER ever entertained the LTFT's and STFT's tuning method. Total pain in the ass and ALOT of work to get what takes a fraction of the time using wideband error in the scanner...AND SAFER!

You really as a noob should entertain some options outside of Hp Tuners Forum: ask/wait/guess/play/scratch nuts/wait/pray for response/exictement someone cares/fixed for you or by you/back to square one of maybe you learned something or maybe someone did it for you out of frustration. See there are only a handful of helpers on here and no one is getting paid. You will recognize a few that I follow like a heal nippin' pup around here...once you find them...read every damn thing you can from them...I read all the way back to when they first started on most...Anyhow the good helpers are the ones that are literally out busting balls on larger tuning issues. I'm a noob helper cause well I know just enough to get me in trouble and hopefully if I can keep these guys out helping others I figure I can only learn more if they explaining my next progression.

You can either take an in person coarse (big bucks way-more informative) Greg Banish -Calibrated Success OR take an at home coarse (mid bucks way-informative but still with a few questions) i.e. The Tuning School Learn at Home Basic/Advanced Coarse. They actually both write books and teach coarses. I have used both providers for...well both. Expensive but again I'm a TIGHTWAD! Lol It was totally worth it and I would do it again in a heartbeat. Notice neither are the low buck way which is where you are today. Welcome!

[Speedjunkie99]

Normal daily driving in closed loop is a mix of your VE/MAF tables. See your vehicle uses your MAF ALONG with your VE table up to 4k rpm's. They are constantly blending back/forth to keep things in check with your chosen stoich value. Your MAF is not able to keep up with transient (quick) changes in throttle response (i.e. quick blip of throttle or wot all of a sudden) on its own so it is constantly looking to your VE table for refrence of what should be happening. Consider your VE table the idiot proofing for your MAF. If it doesn't agree or just can't be calculated immediately by your MAF its calculated by checking against your VE table and its mixing time of what is/should be happening that is used.

Now anything over 4k your MAF is the ONLY table working regardless. Hence the wide open throttle refrence of MAF only. Your VE table is nill...void...not taken into consideration at this point unless...

your MAF is being taken out of the equation for some reason. For example...

IF you are going speed density. Speed density= no MAF.

Ahh I follow you now. I will load the current tune in the car when I get in this evening and see if it gets my wide open throttle back to 12.5 or so. I would like my idle and cruise to be a 14 - 14.50 well see where its at this evening after i load the current tune... Thanks Again for all the help guys...

[Speedjunkie99]

Well for starters the car was bought just to do some bracket racing on the weekends and one day in the future turning it into a turbo car. The car will only be driven 1/8th of a mile at a time once its tuned. I want to get the tune accurate before I install my stall. I am installing a PTC Super Street stall should be around a 4000 rpm. But if i get the tune right with the stock heavy converter it should have better throttle response with the stall dont you think...

[Cantalope Kid]

Well you sure as heck want a good starting point for you current modifications so yes. Start from scratch in my opinion. You never know what another tuner did (despite using the compare feature) as the why the changes were made is always missing.

[Speedjunkie99]

Ok well, set everything back to stock except for my shift points and modified my PE table to where i should be at 12.5 afr now. I am still getting about 11.5 at WOT and at idle and cruising I am still getting 16:1 AFR which totally scares the hell out of me. The Idle a cruising is what is going to tear my stuff up and I dont know why it is like that. I upgraded to Speed Density tuning so if I can do away with the MAF I would like to just take it out of the equation all together. I am going to include the tune and the scan after the modifications. I cranked it up and let it idle no throttle help at all and then went and stomped the hell out of it to see about WOT.