Lean Cold Open Loop AFR Issues

[SOMhaveit]

I'm wondering about the relationship between B3605 Commanded Fuel In Cold Open Loop and B4307 Desired Airflow. I had my RAFIG all dialed in and have my VE pretty close but I'm having this problem with lean fueling until I get to ECT of 80*C.

I adjusted B3605 to make the AFR better @ cold temps but it looks like it affected RAFIG. I redid my RAFIG and cold AFR went lean again. I'm at 17 to 18:1 AFR in some temp cells an then 11.8 in others and it isn't a progression, it's sort of all over the place. Is there another method to get cold open loop AFR closer? It kind of looks like I'll just be chasing my tail adjusting B3605.

I have read that this lean issue is a common SD problem but have yet to see a solution on any boards. I'm sure someone has solved this riddle. Can any of you guys shine some light on this?

[SSbaby]

If you richen up the mixture it takes more crank turns to fire up... and as you put it, ruins your RAFIG calibration as it requires more air to mix with the extra fuel.

What's your VE table like, are your values consistent at idle vacuum for 400/800/1200rpm rows? If so, what AFR are you commanding?

[Delco]

A0008 and A0014 in the custom OS sections are your solution

[SOMhaveit]

If you richen up the mixture it takes more crank turns to fire up... and as you put it, ruins your RAFIG calibration as it requires more air to mix with the extra fuel.

What's your VE table like, are your values consistent at idle vacuum for 400/800/1200rpm rows? If so, what AFR are you commanding?

Commanded cold is around 11:1 @ 32*C and rises as the ECT rises.

My VE table is pretty good. Idle vacuum is around 43 kPa. Once the ECT reaches 80*C my idle AFR is between 14:1 and 14.7:1 with commanded @ 14.63. It's normally right at 14.0:1 at idle but there are some momentary blips.

I really wasn't planning on one of the COS. I figured I'd plug the MAF back in and dial it in. I don't know enough about the COS to know if you can even run the MAF or not. I'm just now getting the hang of the rudimentary functions of the OE operating system.

[joecar]

You can run the MAF with the COS.

[SSbaby]

Have you changed your Decay Delay/Decay Rate tables from stock?

[SOMhaveit]

Yes. There's a fairly comprehensive thread about eliminating surging that recommends adjusting those values and that's one of the things I did to get rid of my surge problem. Right now I don't recall exactly what the adjustments were.

I went out this evening and checked it again and it was still lean compared to commanded AFR but it didn't rise above 16:1. I'll check it again in the morning.

[SSbaby]

I'd return my restart enrichment, decay delay, dealy rates etc... tables to stock just to see if the problem is eliminated.