vuss

[bensvuss]

Hi guys, im extremely new 2 the vcm program. i have done a basic scan of the car and read and completed a 2 credit purchase with my licence. Im unsure of how to make corrections 4 exhaust, coldair intake, high lift roller rockers.

[5_Liter_Eater]

You really need to read some of the stickies to get a basic understanding of things. Asking to be spoon fed won't really get you far. Check the tune repository for tunes of vehicles like yours.

[Bill@HPTuners]

A great read for anyone starting out http://www.hptuners.com/forum/showthread.php?t=11178

As for comparible files, check our repository.

[Arron]

Have you flashed in the HSV tune or did you coppy the value's from the HSV tune into your tune ?

the utes tend to have the max torque setting set to 100Ft Lbs and it controls the fuel pump so increasing that figure may cause you to stay lean at wide open throttle .

[Arron]

Hi thanks 4 ur help, I copied the HSV values into my tune and the following figures were therefore changed on my tune tree; including the
MAX TORQUE TO 350 FT,
TRANS INPUT MAX 4425000,
TRANS OUTPUT MAX 4425000,
FRONT AXLE MAX 41943039,
FRONT PROPSHAFT MAX 41943039,
REAR PROPSHAFT MAX 41943039,
So as what ur saying is that i should decrease my torque to 100ft, why is this figure different in a hsv? Will the other increased figures still be ok, or will they also need to be corrected? Any advice is greatly appreciated.

Just changing the MAX TORQUE back to 100 ft lb's should be good (if that was what it was in your stock tune), if you hold the mouse pointer over over that parameter in the editor it will give you a description of what it does in the bottom of the window.

[bensvuss]

Hi thanks 4 ur help Aron. I corrected the max torque back to syandard 100ft, it feels a bit better, but it's still not a 100% still feels like a bit of a miss. I dont know if u have any other ideas, of things that i can try?

[SSUte01]

Hi,

There are a few things in the tune that appeared a little a miss. I have attached a tune below that I want you to try. It is set up for MAFless, if you have retained the MAF, just means you will have to spend more time on that than just the VE table.

What I recommend you do is try it (at your own risk of course) but compare your stock file and this attached file first and have a look at all the differences and then search the stickies and search in general to read up on the things I changed for a basic bolt-on. This will take a bloody long time, many years for most people and even then you learn something every day

Once you have tried it then use both NBs and WB to get the VE table spot on (it should be plenty rich enough (safe) to start with and make the commanded AFR equal the actual AFR (AFR error and STFTs = 0)

Play around with timing to find what works best for you, this is base that I use and go from there. Make sure your car is mechanically sound first.

I noticed you had the injector flow rate of a VTII which would've made your car run about 8% rich everywhere and possibly causing your 'miss'.

This tune is not perfect by any stretch of the imagination and not 'spoon feeding' but it is a good start intended to make you read up and learn yourself. The only 'right' tune for this car is the tune that you make suit 'this' car. Hopefully this gives you more questions than it answers as this is the best way to learn IMO

I hope this helps you learn more and BTW I just saved your file so there should be no need to copy and paste just plug and play.

Good Luck
Luke

[bensvuss]

Hi Luke, thanks 4 ur help, it's gd 2 know that there r some gd guys in the world. It takes an experienced eye 2 pick errors, and its crutial 2 know where u have made made mistakes, in order 2 correct them. Thanks 4 pointing them out. I cant wait 2 check out your tune.

[Arron]

It sounds like you need to do a Vats re-link
link

[Arron]

Does the fuel pump run for a second or so when you turn the key to on ?

Does the car fire up for a coupple of seconds then die ?

[bensvuss]

Hi guys, thing are starting to happen with my tune I have finally settled with my cars current setup. It's now maffless, with the maff unplugged and removed.

I have a question, with reguarding the maff sensor. Could someone please look at my tune and see if i have dissabled everything correctly to run this set up? As i thought that I still may be getting the signal for the maff, as the pcm goes through its standard read cycle, because i read that this could be a problem when disconnecting the maff.

Im currently trimming down the VE, by logging my STFTS. No wideband still as yet, i would like to get the ve close up to 3200rpm first, its still a bit ritch but getting closer. Is there a basic way to get more accurate data at different temps, because i do to logs and the fuel trims are averaged but the morning is lower than on the way home. Is there a way to standardise this information?

I was and still am getting some kr, but it's not audible and i think that its false knock due to the ritch ve, and it's decreasing with modifying the trims.

But as a whole is a bunch better than the maff set up, still always learning. If someone replies could they try to make it clear to understand as im not really up with all the lingo and im still learning the software, just dont want to waste peoples time,

Thanks guys

[TiredGXP]

You said you unplugged the MAF, that should cause you to go into Speed Density mode. Noticed that you set your MAF DTCs to 2, which is good. You might want to consider also setting your MAF fail frequency to 0 (ok, its redundant when you have unplugged the MAF, but it can't hurt).

Noticed that you have set the LTFT to disabled, and have STFT Open Loop to disabled (now there's an odd one, this gives you the option of using STFT when in open loop, which is really closed loop )

Your closed loop enable ect vs iat table will leave the vehicle in closed loop operation.

Looks like you have things set for closed loop speed density.

[TiredGXP]

I am trying to use my scaned stfts to modify my new ve. Im doing this driving at loads on the way to work. I dont want to use my ltfts as they will mess with my fueling, I think still learning. Because stfts are the only trims that can be learned i think. I still dont have a wide band so im only using stfts up to 3200 rpm, but good news i just ordered one.

A couple of things:

STFT's are not learned - they are driven directly by the narrow band o2's. LTFT's are learned based on long term averages of the STFT's. Many people prefer to use only STFTs like you are doing because you don't have to waste time and fuel driving around until the LTFT's relearn, so you are ok with STFT's

I did another scan today and my stfts increased from -1.6 and -0.8 up to like -6.2 and -7.0 after i paste specialed the trims into the ve from the day b4 and re flashed. Now im confused?

See below, but also ensure that you have the engine at normal operating temperature before logging. Smooth driving (throttle transitions) is important to consistent results when dialing in the VE table. If you had a WB you would see how transient rich and lean conditions exist on rapid throttle transitions.

Im not sure what u mean with the closed loop speed density?( how come when you use computers, that comes hand in hand with big words and lingo that i dont fully understand.

OK, terminology (jargon). An engine runs in several modes. When fuel trims are enabled, this is known as closed loop - because the narrow band readings provide feedback to alter the fueling. When you disable all fuel trims, there is no feedback from the narrow band o2 to adjust fueling and this is known as open loop.

Maf mode provides a direct measure of air mass. With the MAF disabled, the ECM uses pressure, termperature, RPM to estimate airmass. This mode is known as "speed density". You can be in either open loop or closed loop in either MAF mode or Speed Density.

Also is there a way to get consistant stfts in all ambient temps as my trims are also different night to morning?

Oh, man did you ever open up a can of worms here

In theory, the cylinder charge bias and bias filter tables are supposed to compensate for day to day temperature changes, but adjusting these values it is not intuitive or really well understood by many people (there are exceptions, but not me really). Check out these links for more discussion of the issue:

http://www.hptuners.com/forum/showth...highlight=Bias
http://www.hptuners.com/forum/showth...highlight=Bias
http://www.hptuners.com/forum/showth...highlight=Bias

If possible, try to run your logs at roughly the same time/temp conditions to help out with consistency.

[TiredGXP]

Thanks 4 ur help buddy, So in relation to me trying to log STFTS, i need to re enable LTFTS in my tune...... because this is the master switch, to do so? That would then put me correctly in closed loop, right......?

I have made the changes could you have a look to see if that it is now correct to do what i want to do, log STFTS to trim my VE.

I have a 1 bar speed density enhanced tune applied.

B 4 i scan i reset the fuel trims thru the VCM controlls and then set them to learn is this right as i do this anyway?

Thanks 4 the links will have a good stickybeak and see what i come up with.

I have ordered my wideband, so soon i will see, i hope that helps make things abit clearer and not further muddy the waters.

I didn't also relise that throttle transitions had to be smooth and consistant, because my driving is not very smooth and consistant, i give it hell. Shes lucky that it's an auto! So ill try to be more consistant with logging at set times, i usually scan for about fiveor ten minutes is this long enough?

Thanks mate.

As long as STFT's are active you are in closed loop, no need to reenable LTFT's. Your tune that I looked at last night was set up to have STFT's active, so good to go. Go ahead and reset fuel trims....

Five or ten minutes of logging will not provide enough data. You want to drive long enough to get at least 10 hits in each of the histogram cells that you are likely to hit (you won't really hit the high rpm low MAP cells or the low rpm high MAP cells very often in any driving situation, so don't worry to much about those cells.) Some people say that 5 hits per cell is sufficient, the tutorial says 50, so go with what you feel will give you a reasonable average for the cell. I typically do my data logging on my commute to work (35 minutes of combined city/highway driving each way)

The issue with low cell counts is that the fuel trim recorded in the histogram could be a result of a throttle transition and the fuel trim is not necessarily representative of steady state driving at that MAP/RPM combination. The more hits in any given cell, the more likely that your data isn't being skewed by transient conditions.

[bensvuss]

Hi guys, Thigs are getting closer with my tune. I have posted my new scan and tune, do you think that someone could take a look, any feedback would be great!

Thanks guys,
Ben

[TiredGXP]

Your mailbox is full and will not accept any new messages

Log shows a Commanded AFR of 16.5 to 16.6 when not in PE? You really need to get that back to stoich - this could be a big cause of your KR

[bensvuss]

Hi again Al, Thanks again. I am unsure of how to make the changes to get it back to stoich, and im not to sure of the reason behind this , could you please elaborate. Thank you Al Ben

PS Mail box should be gd to go, thank you.

[TiredGXP]

It looks like your vehicle has "Lean Cruise" enabled, If you look at the subtractor table under Engine--> Fuel Control-->COT/Lean Cruise, it should be removing fuel in cruise cells, but not to the extent that I saw in your log.

While you're working on your VE table disable lean cruise by Maxing the Enable and Disable speed.

I see evidence of lean cruise from 800 to 3600 rpm and dynamic cylinder air from .08 to .56 g/cyl.

[bensvuss]

It looks like your vehicle has "Lean Cruise" enabled, If you look at the subtractor table under Engine--> Fuel Control-->COT/Lean Cruise, it should be removing fuel in cruise cells, but not to the extent that I saw in your log.


I checked my tune, COT is disabled.


While you're working on your VE table disable lean cruise by Maxing the Enable and Disable speed.

Do you mean maxing out the Temp Thresholds?

I see evidence of lean cruise from 800 to 3600 rpm and dynamic cylinder air from .08 to .56 g/cyl.

How do I fix this?

[TiredGXP]

Check out the first attachment for disabling Lean Cruise. I've also attached a few histograms that let you compare KR in cells with a commanded AFR > 14.7 to cells where a lean AFR is commanded

Attachment 9285 Attachment 9286 Attachment 9287