Open loop question

llms07 · Post by **llms07** » Sun Oct 11, 2009 8:36 am

normally on closed loop, i believe, your ecu gets feedback from your O2 sensors to adjust your A/F ratio, therefore you dont run lean or rich. when you run in open loop, what does your ecu get feedback from? I heard it gets it from your ECT sensor, is that correct? or does it just run off established fuel setting saved in ecu calibrations?

kinetics · Post by **kinetics** » Sun Oct 11, 2009 12:23 pm

I believe it's a combination of ECT and IAT.
Check your fuel compensation tab, you'll see what I'm talking about; I'm pretty sure that's all it uses, and doesn't try to do any further compensation.

FreshDA9 · Post by **FreshDA9** » Sun Oct 11, 2009 7:50 pm

your rpm and map will tell you where your at in the cell areas, after tuning these areas and still running open loop if there is any weather altitude or engine temp change the Iat and Ect will correct for what you have stored in that each cell as you drive.

H22A_lude · Post by **H22A_lude** » Sun Oct 11, 2009 11:43 pm

What is closed loop for? I've tried putting it in closed loop and it runs like crap. So I'm supposed to have it in open loop all the time? That's what I've been doing anyways.

Martian · Post by **Martian** » Mon Oct 12, 2009 7:33 am

Closed loop utilizes all sensors to make adjustments to air fuel and timing. Open loop references tuned cells, IAT and ECT sensors.

Post by **Spunkster** » Mon Oct 12, 2009 10:11 am

closed loop does not make any changes to timing.