Question about closeloop.....

[Pandor]

Please re-read my question. I understand what closeloop is, and why/how it works. What I need to know is, what is the difference between o2 fuel trim (under fuel trim menu) and closeloop correction trim (under closeloop settings menu) As I said before: Isn't the o2 fuel trim a closeloop correction trim?... To me they sound like one and the same thing. I'm not saying the wiki or helpfile should be a \"how to tune\" dictionary. But having a small explanation on what the options does and in what condition it applies would save a lot of headaches. Knowing how to tune is one thing, knowing how the software works is another thing...

[JaredKaragen]

I believe the difference is when in the code the trim is activated.... But I am unsure why it is in two locations myself. I believe since Calvin had to change the closeloop routine to make provisions for 'wideband as closeloop' he added the feature to the routine. It could be the same correction that could theoretically be applied twice in the same ROM; but is where it's taking that 20% in the middle of all of the other calculations that makes a difference. Same as if you were to adjust the overall fuel trim instead of the injector trim in the injector utility.... They would take place in the wrong time and thus cause an inflated/deflated correction. There is discussion on using the fuel trim or injector trim to offset maps. I believe they apply to your question but just on a different subject matter. I guess in short: each trim is in a different step of the fuel injector fuel value calculations, and if the trim value is in one place it can be different than if calculated at another point. Example: 20% of fv is a lot different than 20% of table value. I can not be certain because I didn't write the app, but this is the best advice I think can be given by anyone but Calvin.

[thething96]

When I started my cal, I used a stock p28 rom, started by adding +%20 on the injector offsets. Did a street tune on openloop only. Had afr's set up good enought under all loads, then finished the cal and had the car run on closeloop till 700-750 mbar. As it sits, the car runs ok, but I noticed that runing the car on crome under same afr's and conditions, the car, at steady 2-3% throttle, is very stable. But having o2 fuel trim at -20 really helped. Also, after having o2 fuel trim at -20 helped with tip in a lot. Might try other options, but I don't know where else to go from here. Motor mounts are next..................