Hi, Which is the best way to richen up the idle(cell16) wide band reads around 15.1, I would like it to be .13.5

 

Hi, Should I change my MAF cal or VE table?

 

Why would you want to richen it to 13.5:1 at idle, and waste fuel? The PCM is hard coded to run at 14.7:1 in closed loop/part throttle operation. That is the A/F ratio that produces decent fuel mileage, and the minimum combined amounts of the pollutants CO, unburned HC and NOx. In fact, running at 15.5 - 16.0 would produce better fuel mileage, but would increase NOx production.

What do you feel you would gain by wasting fuel in closed loop? Its not going to produce any power. When you apply the throttle to produce power, the PCM shifts to power enrichment (PE) mode, and sets a much richer target A/F ratio, that will make more power and torque. Unfortunately, the stock programming typically produces a target A/F ratio of 11.7:1, which it too rich. Reprogramming the PE tables to lean it out to something in the range of 12.5:1 to 13.0:1 will gain you anywhere from 10-15HP.

 

Hi, Thanks, that is what I was looking for. I just want richen it up a little. I am at 15.1 at idle in drive.I wasn't sure if it could be done? Thanks Ray

 

Here's something you can use along with, or instead of, changing MAF Calibration or VE tables for idle AFR tweaking.. Can be used for intake systems that flow differently than stock at idle or in the lower AFGS conditions. You can play with the " Individual Cylinder Fuel Trim Multiplier" table. Adding or subtracting a percentage to the values alters the fueling calculations. EG: if your 3% rich at BLM cell 16 then multiply the 'At Idle column' by .97 to reduce fueling 3%. Conversely if you are lean to add fuel multiply by 1.03. The 'Off Idle' column in the table is used for low throttle conditions it cuts in at TPS>0% and cuts out with a constant table setting " Ind. Cyl Fuel Trim Disable TPS%" stock cutoff is TPS=14.8%. I used this and calibrating my MAF tables. Seemed after the cam and 1.6 RR's my idle and low end went towards the rich side and my high end went towards the lean side.

 

Hi, Is that in TunerCATS, I have LT1 Edit. I just purchased TunerCATS. I have not played with it yet. Thanks Ray

 

Ray, TunerCat 'Tuner' program has one table with a column for each setting (idle & off idle) plus a constant setting for the TPS% disable value. Look under fueling sub section for tables and constants. TunerPro RT has a separate table for each setting and I could not find the TPS% disable constant or Scalar as TunerPro calls them. I do not know about Lt1 Edit..

 

Hi, OK I will try that tune and see what happens. Thanks Ray