razor02097

Which would be better? Changing the individual cylinder fuel trims or recalibrating the MAF for the idle RPM values. It is only in cell 16 I am getting between 135 and 140 BLM values for both banks. While driving, the other cells seem to stay between 125 and 130.

Right now all fuel trims where set to 1.0 to correct a BLM split that mysteriously popped up after header install. MAF calibration is stock, I do have an aftermarket CAI but the MAF has been cleaned already before data logging and tuning

I know they won't be dead on 128 due to so many variables so I would like to lower the BLMs to between 125 and 130. That is the goal.


Searching for this turns up "idle issues" threads by the zillion, and CZ28 search doesn't seem to like me much anyway

Thanks.

95Blackhawk

I would start with making sure ALL air is going through the idle air plenum. This means checking your TB and closing it all the way, if not already. Once you do that, go back to stock cylinder trims then start playing with MAF calibration.

razor02097

Posting follow up

Setting all fuel trims at idle to 1.00 and adding 6% to MAF calibration table 1 frequencies 2384, 2512, 2640 fixed the issue. The TB is stock and unaltered. BLMs are 127-129 consistently. I can start the individual fuel trims now.

Thanks.

95Blackhawk

Any blending of the tables? The MAF is not just off on cell 16, it is off on the MAF tables but shows up in cell 16. Big jump for the computer without slowly blending back into the stock tables.

razor02097

I didn't add to the entire table... but yes adding 4% to 2768, 3% to 2896, 2% to 3024 then 1% to 3152 did blend the table.

I still have data logging to do.