On a cold start ( like 30 or 40 degrees) my afr starts in the high 11s for about 30 seconds before it slowly works its way up to 14s about a minute later. Is that too rich to cause damage over time like washing oil or whatever? Id like to not run into issues down the road from this

 

No its fine. Im in the same boat. Whatever idles the car well.

 

About what my car does. have you ever had a wideband on a stock civic or integra with a oem ecu? You will be surprised how rich they run from the factory!

 

I had the wideband in on stock injectors and ecu right after i swapped it and for whatever reason it was dumb lean like 18:1. The engine is a b20 and it was with a ls ecu

 

It takes alot more than that to wash out cylinders. You can trim back your ECT fuel correction or the post start fuel trim.

 

I don't mean to be off topic, but I'm curious. my idle when cold is similar... at around 11.8-12.2. but when I first start the car, I have to hold it the gas pedal for about 30secs. I've tried playing with cranking fuel, post cold start.... anything else I can try? it's a s300 btw

 

Bringing this thread back to life bc I have the same problem with my s300.

B20b engine 550cc injectors. First start up cold engine and cold weather makes my car run rough and rich. Like the guy I quoted from above, I have to hold the pedal to make the car Rev to 1500-1700 for like 15-20 seconds in order for my car to not run rough. After holding the rpm for those seconds manually with throttle I can take my foot off the throttle and idle will stay above 1000rpm on its on and fuel starts to lean out.

If I just start the car without manually pressing the pedal, the car will bounce around very low rpm and almost kill for the same time frame I have to manually hold the pedal. It seems there is not enough air getting in bc the idle won't go to 1500rpm like it should during a cold start. Car starts fine if it doesn't sit for hours to cool down completely. Drive fine as well. The only problem I'm having is this initial start up.

I lowered the correction on the fuel compensation tables at low/idle tables. Then I also took fuel out (-10%) in the post crank parameter. Does the same thing every time. Goes into the low 10s when all this going on. This is after letting my o2 sensor warm up before cranking so I get accurate readings right off the bat.

Anyone have some suggestions?

 

Decrease cranking fuel in the lower temp regions. Decrease ECT fuel enrichment in the lower temp regions too. Its clearly too much.

 

I will try to adjust them further when I get off work. I have my laptop with me to make the changes. I will update after I make the changes to share my results.