Need help, I'm getting reduced power and a P0068 code with my new 427 and YSi

I'm tuning my new 427 boosted by a YSi supercharger on my 2004 vette. I am having issues with going full throttle with the current tune. Here are the related codes;
P0068 - MAP/MAF - Throttle Position Correlation (Old) (History) (Immature)
P0102 - Mass Air Flow (MAF) Sensor Circuit Low Frequency (Old) (History) (Current) (Immature)
P0103 - Mass Air Flow (MAF) Sensor Circuit High Frequency (Old) (History) (Current) (Immature)
C1278 - TCS Temporarily Inhibited By PCM (History)

Presently I’m running a 2 bar tune (plan to upgrade to a 3 bar once I have thing running good).

- I have adjusted the P0102 and P0103 from no mil light to mil on first error with no luck (I ran no mil light on the previous engine tune up to 12lbs of boost with no issue). I have also changed the KPA of each.
-I was running the P0068 error table at the max 4.1 and it would still go into reduced power. I brought it down to 3.0 with no luck also.

I have attached the tunes I’ve tried with the scans showing the Reduce Power happening.

I’m at a loss right now….. :banghead:

This is from the 4th gen forum sot the tables are a little different but same issue.

http://www.hptuners.com/forum/showthread.php?t=28854

Basically max out the calc airflow table (4.1) in angine diags/general.

I did see the thread you linked, thanks. I've tried maxing the table with no luck...

Still getting P0068? Attached is my old C5 w/ A&A tune. Hope it helps. Try duplicating my engine diags/general numbers on all tables/fields.

Thanks for the tune to look at. How much boost were you running on that setup?

I have my old tune which was a 2 bar and I copied that for all the basic stuff. I'm guessing that the extra air flow going from a 346 @ 12 lbs to a 427 @ 15 lbs so far is the issue.

Quote:

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Originally Posted by 5_Liter_Eater

Basically max out the calc airflow table (4.1) in angine diags/general.

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That effectively removes all the safety checks for a runaway throttle condition. :bigshock: That's bad... Toyota bad, if you catch my drift...

Right but I'm just trying to pinpoint the problem. In the link I posted I said that you should remove the restriction temporarily to be able to tune the table. I guess I should make that same statement here. :)

So max out the calc airflow table and dial in the tune. then, do a scan getting lots of TPS and RPM data trying to cover a lot of the cells in the calc airflow table and create a histo that plots the max g/cyl in each cell. Copy and paste that into the calc airflow table and add ~10-20% to all cells.

Scale your VE and IFR by about 30%. You can start with a lower %, but you'll probably end up about 25-30%.

Try this one. Watch your g/sec, as you may end up in a different area of the timing table.



Attachment 23002

PS, if it works, you may wanna start over with your tune, and scale by 5 or 10% at a time until it's gone.

Quote:

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Originally Posted by edcmat-l1

Scale your VE and IFR by about 30%. You can start with a lower %, but you'll probably end up about 25-30%.

Try this one. Watch your g/sec, as you may end up in a different area of the timing table.



Attachment 23002

PS, if it works, you may wanna start over with your tune, and scale by 5 or 10% at a time until it's gone.

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Thanks for the help, I do have a few questions about what you changed. So you are basically saying to lower the injector flow in the tune below what the injectors actually flow. This effectively causing more fuel to enter the engine. This is compensated by a lower VE table.

The engine demands less fuel from the lower VE and actually gets more flow due to the injector flow table.

Makes sense, just wanted to be sure I am understanding things.

Just in case Ed is busy. The answer is yes. All of these values are combined in a way that calculates airflow (aka dynamic cylinder air). That airflow cannot reach a certain value. If it hits that ceiling, you will enter reduced power mode and get 1514 or 0068 along with 1278. Don't forget what he said about watching your spark tables as this rescaling process will move the cells to lower dynamic air values on your table where your timing is currently higher. Those new higher timing values can cause detonation and you know what follows. :hi:

Quote:

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Originally Posted by blownbluez06

Just in case Ed is busy. The answer is yes. All of these values are combined in a way that calculates airflow (aka dynamic cylinder air). That airflow cannot reach a certain value. If it hits that ceiling, you will enter reduced power mode and get 1514 or 0068 along with 1278. Don't forget what he said about watching your spark tables as this rescaling process will move the cells to lower dynamic air values on your table where your timing is currently higher. Those new higher timing values can cause detonation and you know what follows. :hi:

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Thanks,

I'll give it all a try tomorrow :cheers:

Got the P0068 code fixed by lowering the VE and the injector flow 30%.

Thanks for the help :cheers:

Bringing the topic back from the dead.

I keep getting the P0068 code under WOT. I have tried to scale it 30% and various things and it still does it.

Never had a issue until this 2004.

You know the drill....post the tune. Let us have a look. :)

Quote:

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Originally Posted by blownbluez06

You know the drill....post the tune. Let us have a look. :)

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Hah! I ended up scaling the ifr and ve 50% and got to finally do a wot pull to 5,500 without going into reduced power mode and car leaned out. Every other pull the car would last 1 second before the car Would freak out.

Now onto the issue of fixing the fp drop from 58 to 20 lol.