Ive changed my LC-1 analog output to simulate 14.8 - 15.8 afr = 0 - 1v. Which has leaned out my crusing afr to ~15.2 - 15.3. Which is what i want, but before my meter would cycle a small ammount 2-3 segments (~.3 afr), but now with the leaned signal, it will stay around the 15.2 mark and then jump to a mid 14 and then back into 15.2-15.3, so im bouncing around 5-6 segments (~.8 afr). I think it has to do with fuel trims, but the ecu THINKS its in a good afr (~0.5v). I dont understand why the Ecu is returning to the mid 14's when that is going to be >.8v on the NBO input. I know it cycles ~.4-.7v normally. My therory is the fuel trim is getting >5. I think it uses the Injector pulse width to calculate the estimated afr , which it sees as too low. The fuel trim gets out of range, and it resets the trims to 0 causing Injector Pulse width to go back up, making my afr to to 14, then fuel trims start going again. All this happens about 1-2 times a second crusing. Its not a steady afr at all, unless you call 14.5 - 15.5 steady .
Also i get random times coming off throttle that it will stay in open loop before it returns to closed loop, not sure why. The afr will stay at my richer-just-came-from-boost values ~11.0-11.5, but they stay for ~5-10 seconds before returning to closed loop values. My LC-1 is set for 1/12 second updates, so that cant be the delay. Any suggestions?

P.S. I think closed loop tuning is not fun. Open loop is fun.

 

could it be the ecu is switching to open loop momentarily as some sort of internal check? Try leaning out your fuel map in those areas. If it doesn't work you are not out anything anyway.

 

That was my next step, i read that the fuel trims based on % off from the fuel maps, so if i lean out the 0-80 load and 0-7500 rpm that should bring it back. Ill do that and post back tommorow afternoon, im also trying out the NLTS Tephra v5.8 rom tommorow morning. Heh guess if i dont post back, you'll know one or the other didnt go right

 

Just curious, why don't you scale analog output from 10.0 afr to 20.0 afr (0-1v)?

 

Try these settings ...

.82v = 14.9 AFR (I use 15.3)
.1v = 16.0 AFR (I use 16.2)
Instant response ... no delay.

This is currently working fairly well for me. Using the delayed readings works for smoothing out the idle because of the distance of the LC-1 from the head, but at a cruise state the exhaust velocity increases making this distance unnoticeable.

Sub7, you can't scale the 1v output that way because the ECU will apply a certain amount of correction based on the voltage reading ... if the curve is super wide like you've described, the voltage swings in closed loop will be very small and the ECU will make very small correction for big differences in AFR. The same goes for a very short curve ... the ECU will make adjustments too large.

 

Noted, thanks!

 

Cool, thanks ill try those settings on the way to work tommorow.