50f00 AFR at idle issues

[Fortmac180]

have innovative wide band and its also simulating a skinny for ecu. idles and afr s good for a bit then starts running rich ..??

also while running rich timming seems all messed up. i give it a blip, afr and timing somewhat stabilize for like 10 sec then starts running rich.
info idle turned up on purpose from correct screw
ill attach a log of it at idle
if u need more info just ask, thanks a bunch.. ps its -18c but been doing this since early fall or earlier

[Matt]

What are your O2 voltages out of the wideband reading?

What is the coolant temperature when you notice the issue

I'm wondering if the wideband simulated input when it gets used after attempting to go close loop is putting out a different signal to that the ECU is expecting. We dont have the O2 rich/lean voltages for this at the moment but could look in the code for them

[Fortmac180]

hey matt thanx for fast reply, its now 12 30 am here so i assume somewhat morning for u.

reviewed the log and in closed loop o2 voltage is bouncing around from like .13v (15.6 afr) to .97V (14.2afr), then when it starts to run rich it pegs over to 1.14v (13.5afr) but continues to drop and then bounces around from 12-13 afr and output voltuge doesnt change from 1.14V. also when its running rich ign timming appears to be bouncing from 7-9 degrees btdc.. then i blip again and o2 voltage bounces again - afrs bounce and timing holds 15 btdc with ocasional bounce down to 9 btdc.. then starts running rich again in vicious cycle. ps i can hold 1200 rpm high idle and seems ok just at the 900 rpm idle it pooches out

more info
550s at stock feul pressure stock afm, stock turbo. sr20det

ill attach the bin im using so mabey u can have a peek at log.

ps did a tune a long time ago to run lean where closed loop supposed to like high 15,s afr then never turned closed loop back on, drove it like this for many hours. if that has anything to do with it

thanx a bunch
Brody from Canada EH!

[Fortmac180]

Ps i think in this run particular never got hotter then 74C
PPS since having this car then installing Nistune i dont think i have ever ever seen it use warm maps just cold map
think it has a 70c thermistat

[Matt]

When on idle (TPS idle lit) the timing will be adjusted by the ECU based on the target RPM. If its higher than target RPM then timing will be dropped further. Otherwise 15 (idle/decel) timing is the target timing

O2 sensor seems to be working okay in regards to rich/lean operation when its in closed loop

When it runs rich I dare say its going out of closed loop mode which means ECU shows as richer than 14.7:1

Could try dropping the minimum injection time and then latency at idle to lean it out further and see if it maintains O2 feedback closed loop then

[PL]

I did see something similar to this once when somebody was still running the EGR system. It appeared that the ECU waits a certain time at idle (it was awhile ago but I reckon it was 10 to 15 seconds) and then operates the EGR valve. On the car I was looking at this made a marked difference to AFR's.

PL

[Fortmac180]

Thanks again for the quick reply

I have to go back to work here tomorrow for a week so i wont get to play with what i want to

"Theoretical Pulse width (TP) = MAF Lookup * Injector multiplier
Injection Pulse width = Fuel table [ RPM , TP/256 ] * TP + Injector Latency + Various enrichment"
I will play with these on may days off next week

Also PL in my feedback switch map EGR system is not flaged, also EGR temp sensor off is flaged

thanks again guys much appreciated, keep up the good work over there down under

Brody