Newbie confustion

[samgm2]

I am trying to tune my VE table and did what I thought made sense, but I didn't get the response that I was expecting.

Under Engine Diagnostics->Airflow(tab)->MAF fail high was changed from 13500 to 0.

I verified that P0103 code was set in VCM Scan.

In VCM Scan:

Displays->VCM Controls->Fuel and Spark (Tab)->Reset Fuel Trims

I then drove the car for a three days and took it out to record VE histograms.

I recorded 2.hpl (log file). This file shows that values below about 2800 RPM are rich.

Oddly, values above all show about perfect. Doesn't make sense.

I then adjusted the VE tables based on the values in the table and went out and after about 40 miles of driving got 3.hpl

Now everything is lean by about as much as I took out. It would seem that it was fine before... Very confused.

In case it's needed, my bin is REAL TUNE 1.hpt

My scan config file in case its needed is included.

Any help would be greatly appreciated.

Sure wish autotune was here...

Sam.

[samgm2]

The above should say that in the original scan with the maf disabled, LTFT values at over 2800 RPM were about perfect. All showed numbers close to 0.

Below that everything was about -6 to -8

Subtracting 6 to 8 from the affected values yields LTFT values of about 8 to 11!

What am I doing wrong?

Sam

[FRCTony]

What injectors are you running?

[Russ K]

The above should say that in the original scan with the maf disabled, LTFT values at over 2800 RPM were about perfect. All showed numbers close to 0.

Below that everything was about -6 to -8

Subtracting 6 to 8 from the affected values yields LTFT values of about 8 to 11!

What am I doing wrong?

Sam

You don't subtract, use paste multiply by %.

Russ Kemp

[samgm2]

I am running the LS6 injectors (28.8 pound).

This is a bit of a modification.

It is a Mazda Miata with an LS6. The LS6 is basically stock. Intake air is from the cowl on the miata.

Dual 2.5" exhaust. Fuel rail is at 58 PSI and holds very accurately at all engine speeds and loads.

Sam

What injectors are you running?

[samgm2]

You've lost me.

The instructions say that if you have a -6 in the LTFT histogram, that you subtract 6 from the value at the same location in the primary VE vs RPM vs MAP table.

You are saying than that I subract 6% of the value from the same entry in that table?

Did I disable the MAF correctly. When running the scan tool I still see output from it.

I am guessing that the sticky instructions are pretty old since the directions don't seem to match the current programs.

Sam

You don't subtract, use paste multiply by %.

Russ Kemp

[samgm2]

One more thing, I am using the PCM from a transam and I transplanted all the tables and values from an 04 Corvette Z06.

Sam.

The above should say that in the original scan with the maf disabled, LTFT values at over 2800 RPM were about perfect. All showed numbers close to 0.

Below that everything was about -6 to -8

Subtracting 6 to 8 from the affected values yields LTFT values of about 8 to 11!

What am I doing wrong?

Sam

[Bill@HPTuners]

You are saying than that I subract 6% of the value from the same entry in that table?

No he's saying exactly what he said. You don't add or subtract a %...you multiply a percent against the VE table which is a theoretical percent.

As far as Autotune goes RTT is an extention of our Custom operating systems which means you'd need to apply one of our custom operating systems to take advantage of either. And to make good use of autotune when it becomes available you'll need to understand the fundamentals of tuning ie if your having the autotune feature add or subtract something thats supposed to be getting multiplied you'll run into trouble quicker then NOT using the autotune feature

[samgm2]

Look, I am not math challenged. I am a programmer (in a dozen languages) and I am a Chemical Engineer.

The statement is not clear, that's all.

An example would be nice. Especially since this apparantly is different from what you have in your sticky files:

"5a: Fuel trim approach: Let's say at .800, .28 which is equivalent to 800 RPM's you have 4 which is equal to +4. For ALL YOUR TRIMS you want between 0 and -4, so what I do is do whatever it takes to get to zero. Easy rule of thumb here if you want number smaller, add you want number bigger subtract. So, we want to bring that DOWN to 0 so ADD 4 to .800, .28. Let's say 2.0, .20 is -10, SUBTRACT 10 from 2.0, .20 to bring it UP to 0. This will not work out exactly but will get your PRETTY CLOSE. "

So apparently, the above is not correct. A detailed example of what is correct would be nice and perhaps revising your tuning file might be in order.

Sam

No he's saying exactly what he said. You don't add or subtract a %...you multiply a percent against the VE table which is a theoretical percent.

As far as Autotune goes RTT is an extention of our Custom operating systems which means you'd need to apply one of our custom operating systems to take advantage of either. And to make good use of autotune when it becomes available you'll need to understand the fundamentals of tuning ie if your having the autotune feature add or subtract something thats supposed to be getting multiplied you'll run into trouble quicker then NOT using the autotune feature

[Bill@HPTuners]

A detailed example of what is correct would be nice and perhaps revising your tuning file might be in order.

It isn't MY tuning file so I dunno where you got that from, but whoever posted it can easily edit it. If you think the sticky can do without it in there I will reevaluate that particular thread & remove it from the sticky if need be.

[samgm2]

O.K. It's not your file. You aren't responsible.

I got it off this site. So you can see how others like me could be lead to believe there is some merit to a file that is permanently sticky.

You can also see how this could create some confusion for someone new to using your product...

Does HPTuners provide its customers with any assistance whatever?

Can you assist? Can you provide me with an example?

Sam.

It isn't MY tuning file so I dunno where you got that from, but whoever posted it can easily edit it. If you think the sticky can do without it in there I will reevaluate that particular thread & remove it from the sticky if need be.

[Bill@HPTuners]

Tuning isn't always as cut and dry as you would like it to be, especially when trying to tune for the first time without a wideband. Personally I don't like using trims for other then verification purposes.

[samgm2]

Yes, of course its involved, but the principals are not all that complex as long as I know what the values I am looking at are and how they interrelate.

In addition, it isn't that a narrow band sensor is not accurate. It is simply that it is linear in a very small region and logarithmic outside that region. But once its in its linear region narrow band sensors are fine.

I am asking for the answer to two questions.

1. Did I properly disable the MAF using the procedure I outlined above. The reason I asked is that I continue to get MAF data. In addition, all cell values at high RPMS are zero. That seems unlikely. It appears that the MAF may in fact be doing something.

2. What is the procedure for adjusting the VE values from the scanned LTFTs?

Sam

[Bill@HPTuners]

1. Did I properly disable the MAF using the procedure I outlined above. The reason I asked is that I continue to get MAF data. In addition, all cell values at high RPMS are zero. That seems unlikely. It appears that the MAF may in fact be doing something.

unplug it, that will disable it.

2. What is the procedure for adjusting the VE values from the scanned LTFTs?

www.hptuners.com/help