Open Loop - Closed Loop???? Accel Batch DFIc

[IRaceAV6]

I noticed in the Accel Tech Manual that the ecu can be configured to Closed loop operation. Is this a misnomer in the manual that applies to other cars and not ours?

Curious because it would allow the O2 to provide air/fuel information to establish a 14.7 air/fuel ratio. Too lean? What is ideal? Looking to pass the dreaded smog test. Stock heads, stock cam, all the smog system is there to include a brand new 3" high flow Cat Converter.

Looking for suggestions.

Thanks!

 

[Reggie West]

The closed loop mode will force the A/F ratio to 14.7 to 1. The way to control that is you can set the box to stay in closed loop mode by a percentage of the throttle.

The ECM will reference the O2 sensor to get the info and it will use whatever value it needs to correct the A/F ratio back to 14.7 to 1. Regardless of what values you have put in the fuel table.

Hope this helps.

 

[Scott231]

Correct Reggie. And note, that function is for non-wide band Oxygen sensors and will only be accurate to stoichiometric air/fuel ratios.

 

[PaulRV6]

One other thing to keep in mind for correcting back to 14.7:1. The system will only correct back a certain amount (built in) depending on throttle position. At idle it is +/- 5%, WOT is +/- 18%. It is important that the fuel map be within these percentages.

paul