Controlling Cranking Commanded AFR with E38

[BoostedYards86]

What tables control the commanded afr under cranking? Still trying my best to figure out why my car dislikes starting and finally have time today to get some hours in on her.

[realspeeddan]

If I can join/hijack your question a little, I am also a little stumped with a starting issue 2011 Corvette I am tuning. I also would like to know the answer to your question.

It is Z06 with that is totally stock EXCEPT for a GMPP camshaft # 8895 8722 (227/239@ .050)

I'm mapped the VE stuf with the Bluecat tool. Generally the car runs good and does what I want. BUt on startup it has a log crank bedfore it fires. Once it is hot id sometimes doesn't like to start unless you put your foot to the floor. Sometimes after it starts it acts like it is loaded up with fuel and wants to stall unless you clear it out with the throttle.

I had to take a lot out of the VE table/equation at low rpm, and it acts like it is flooding during crank.so I thought that maybe leaning the Crank FA multiplier would help, but it didn't change much, exept possibly making it a little worse.

I also tried adjuting the Idle Startup Airflow, but I'm confused as whether to go higher or lower on that.

I'm attaching the unfinished tune file in case anybody want to take a look and offer up ideas.

The car also has a bad stumble at high TP & WOT at low rpm, below 1900 rpm, that I havn't figured out yet. More timing at low rpm seemed to smooth it but then sometimes I see lots of KR along with the stumble.

[DSteck]

Realspeeddan...

The WOT low rpm stumbling you're seeing is probably MAF turbulence causing burst knock to kick on and off.

[realspeeddan]

DSteck,

Thanks. I'll look at that. Burst Knock is new to me. (No settings for it in the SCT ford tunes I do.)

So if I turn the Burst Kncok retard Mult vs. RPM down (all the way to 0?) below 2000 rpm that will disable burst inock retard in that area? Or is there a better way?

[BoostedYards86]

Steck, I got the afr to not drop during cranking, but now once running commanded afr until closed cloop engages goes from 14.68 to 7.89 and bounces idle and sometimes stalls out.

[DSteck]

You know the routine. Post a log and the tune.

[BoostedYards86]

there u go if it worked
Attachment 33554

Attachment 33556

Attachment 33557

Attachment 33558

[BoostedYards86]

if that doesn't open right let me know I'll try again