I'm having an issue with the RPM's dropping and bouncing back up when I shift from P/N into gear or when I come to a rolling stop. I have my idle set at 725 RPM, and the RPM will usually drop to 400-500 RPM and then come back up. I have done some extensive reading on EFILive forum and I haven't been able to find what I think I need. Can anyone help me out?

Also, when I am rolling at low speeds and shift into N, the RPM's bounce up and down pretty bad till I come to a stop or put it back in gear.

 

did it start with the warmer weather? may try and bump your running air .10 at a time and see if that helps it.

 

It started when I put the new motor, cam, and TB in, haven't been able to get the idle down perfect yet. I tried bumping the in gear desired airflow up 10% and it still does it. I actually went as high as 30% increase in desired airflow and still same problem.

 

you went from the 5.3 to the LQ9? There is like a 14% diff in RAF in gear and 21.6% diff in RAF in P/N between the 5.3 and 6.0L. Were the increases in the RAF from a 5.3 tune? I would continue to inch up the RAF to see if it smoothes out. hope it works out.

Here are the stock RAF values for a 03 SS.

Gear-19.00000 18.36035 17.45020 15.75000 13.94043 12.75000 11.79980 10.00000 9.00000 7.75000 6.50000 6.50000 6.50000 6.50000 6.75000 6.75000
P/N-17.00000 15.50000 14.00000 13.00000 12.20020 10.90039 9.75000 8.59961 7.79980 7.00000 6.25000 6.25000 6.25000 6.00000 6.00000 6.00000

 

I just compared radix tune vs stock 6.0 vs stock 5.3. All idle airflow settings are same with radix tune and stock 5.3. There are lots of differences with idle air flow in a stock 6.0. Although mine is idling good I am going to swap everything over to the 6.0 settings just to see how it goes. I do see some cold off idle acceleration stalls. Hopefully it will help that out?

 

Maybe I am not understanding the RAF/RAFIG tables correctly. Is the airflow reduced by the amount in the table, or does the table tell you how much airflow is required? The LQ9 values are lower than my 5.3 values, which doesn't make sense unless the values in the tables are subtracted from some other value.

 

Sounds like a RAF problem to me. I dont have EFI Live, But you should be able to make a custom histo and log LTIT+STIT For Park Nuertral. Then LTIT/GEAR+STIT and add that to your Disiered airflow instead of guessing..

 

not to over simplify, the RAF is basically the amount of airflow (g/sec) that the engine is using at idle, amongst a few other things. with a larger duration cam and larger motor it will take alot more air at idle to keep it running.

Base Running Airflow

• Idle Air Flow vs. Coolant Temp vs. (Gear & P/N): This table is used to determine the base airflow (in g/sec) for the IAC/ETC control vs Engine coolant temperature. This is used as a base setting (or startpoint) for the adaptive idle routines and also the base IAC position when the vehicle is moving.

 

I have been logging with the RAFIG and RAFPN and trying to get them to zero, getting close and it's tons better. Finally getting somewhere....it's doing much better.

 

BTW...I went from mid-upper 7s in the In Gear desired airflow to 12's. Big jump