p1514 and no reason

[tazinhawaii]

OUTSTANDING!!! I will try that.

Thus far I have switched to the '02 COS3 op system (from the 2001 years system) with no change and have foved C6101 up and down with no real change. I have also fixed all the other problems (i.e. the out of range issues). I also noticed it would always cut out around the same airflow and RPM. And it just so happens it's usually 2.32 g/cyl.

I will try this tonight. Thank you again.

Derrick

[C3vette75]

What RPM does it happen at?

[Turbo595t]

What RPM does it happen at?

See the picture in my post 10.

[C3vette75]

Brian
I know yours was around 4000 RPM. I was wondering if Derrick's was occuring near the same RPM. Table B0120 has a value of 4000 RPM and it states, if engine speed is above this value, then the PCM will use the MAF sensor exclusively (if not disabled by DTCs) to calculate grams of air per cylinder. No updates are made to the airflow correction factor. I know the the MAF is supposed to be disabled but what if you change this value to 5000 or more.
Will the reduced power occur at the new value?
Joe

[Turbo595t]

Brian
I know yours was around 4000 RPM. I was wondering if Derrick's was occuring near the same RPM. Table B0120 has a value of 4000 RPM and it states, if engine speed is above this value, then the PCM will use the MAF sensor exclusively (if not disabled by DTCs) to calculate grams of air per cylinder. No updates are made to the airflow correction factor. I know the the MAF is supposed to be disabled but what if you change this value to 5000 or more.
Will the reduced power occur at the new value?
Joe

Joe,
Please re-read my post 10. The part in quotes came from something I found on another site. The picture I posted came from the scan log that Derrick posted and is from his car.

[tazinhawaii]

Yes, mine did occur around 4000 RPM, but I already changed that value to 8000RPM to see if it had any effect. It didn't. I reduced the VE tables and IFR's but now I need to go get some gas to try and see if it worked. But I'm in the middle of my son's B-day party now (hiding in the computer room since it's all my wife's hen crackling friends here for it)....

Derrick

[tazinhawaii]

That's what I said as I left off the throttle after hitting 100+ MPH in mere seconds.

OK, there are a bunch of people who post about p1514 codes when going forced induction. Mosst solve it by increasing the C6101 table apparently. But here's the kicker. Apparently the PCM can't handle calculated cylinder airflow greater than 2.32 g/cyl. That ALSO pops a P1514. Thanks GM for not putting that into the service manual. I knocked the VE tables WAYY down and the IFR table as well. Took the car out and it runs like a CHAMP. Only 8 psi right now while I get everything dialed in for that level. Then I'll slowly bring it up to 18 psi (which is what I built the motor to run at - 8.6:1 CR).

[Turbo595t]

That's what I said as I left off the throttle after hitting 100+ MPH in mere seconds.

OK, there are a bunch of people who post about p1514 codes when going forced induction. Mosst solve it by increasing the C6101 table apparently. But here's the kicker. Apparently the PCM can't handle calculated cylinder airflow greater than 2.32 g/cyl. That ALSO pops a P1514. Thanks GM for not putting that into the service manual. I knocked the VE tables WAYY down and the IFR table as well. Took the car out and it runs like a CHAMP. Only 8 psi right now while I get everything dialed in for that level. Then I'll slowly bring it up to 18 psi (which is what I built the motor to run at - 8.6:1 CR).

Derrick,
That is great, thanks for testing it. I got a project coming up that knowing this works, I won't run into this problem.

Brian