How is Startup Commanded AFR Determined?

[G_OCHO]

G8 GT, with 224/228 112LSA, Headers, Exhaust Mods. I'm working on improving cold start and warm up idle. I don't understand how the EQ Ratio and Commanded AFR are determined during cranking mode. If I apply the Cranking FA and the OL EQ Min at Startup ECT , I don't come up with the same number as what shows in the log. I have all the other OL modifiers set to 1. Can some one explain how the Cranking commanded EQ and resuting AFR are determined?

[DSteck]

Cranking impacts just that... Cranking. All the gain tables get used once it is in run mode. Put those tables back to stock.

[Shrek]

With a cam upgrade your issue is probably airflow related. Take a look at the thread linked below ...

http://www.hptuners.com/forum/showthread.php?t=39395

Try out some of the suggestions regarding airflow and spark advance - these may help.

[G_OCHO]

I can teak the idle airflow numbers, I'm not off much compared to the attached thread at least in the 0 to 1000 rpm range. Easy enough to set OL tables to stock. I'll try these. Hot or cold engine starts quickly and when hot the idle is very good. I'm thinking , I should work on the Idle ECT multiplier to address the cold idle. Also, I'm still not clear on what is commanding the very rich AFR during crank mode(note the commanded 5.5 AFR and corresponding inj. pulse of 30ms., immediately goes to Stoich when fires?

[DSteck]

Did you read my post?

[G_OCHO]

yes, I read the post. I'm not sure I fully understand. This is what I think your telling me.
When the engine is in "run mode" the OL gain tables will set the commanded AFR.
When in crank mode, the crank tables set the AFR.
Assuming I got this stated correctly.

Here is where I'm sill confused or maybe gone off into the weeds. The only table I know of , for E38 ECM, that would influence cranking AFR is the Cranking AF table. So based on start ECT 99 F and the Crank FA 1.8 at 0 sec, I would have a commanded crank AFR of roughly 8.2 (14.6782 / 1.8 = 8.2)....... The log shows 5.19. Is this off in the weeds? if so, what is the correct method?

[BMWMD82]

I was under the impression that the open loop gain tables do have an effect on fueling while cranking. Yes, no, maybe?

[G_OCHO]

OL gains are applied after startup, I didn't see any evidence of OL gains being applied during cranking,

During cranking the Cranking Fuel FA multi Stage 1 vs time table is used to set the cranking commanded AFR. This table is incorrectly labeled "cranking time" it should be labeled "Engine Off Time" or "Time since last Start". Stoich AFR/ cranking FA = cranking commanded AFR. I tested this with 5 different ECT and various times between last start and all my calculations matched the scanner value for cranking commanded AFR.

I didn't find any other tables that would be applicable to cranking AFR, Others please comment if you see otherwise.

[BMWMD82]

This table is incorrectly labeled "cranking time" it should be labeled "Engine Off Time" or "Time since last Start".

That makes a hell of a lot more sense to me. I always thought it was referring to cranking time, which didn't make any sense.

I was told the OL gain tables did alter cranking fuel, but maybe that isn't correct.