Drop into Gear stalls Immediately (Cold Engine)
Do you have the idle set higher than normwl? I'd expect so.
That means going into gear can really load up the motor at
idle. What is your MAP reading showing you when you do?
Since you're open loop that may be putting much more
enrichment on you than you really need, making the idling
weaker and slower to react to air steps and so stall out.
Look at MAP and commanded EQ ratio / AFR and actual fueling
(WB) during your cold starts and see if it's crazy rich. The
stock start and afterstart enrichment are mighty high, and
you don't need any more of that action I think.
That means going into gear can really load up the motor at
idle. What is your MAP reading showing you when you do?
Since you're open loop that may be putting much more
enrichment on you than you really need, making the idling
weaker and slower to react to air steps and so stall out.
Look at MAP and commanded EQ ratio / AFR and actual fueling
(WB) during your cold starts and see if it's crazy rich. The
stock start and afterstart enrichment are mighty high, and
you don't need any more of that action I think.
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From: Shelby Twp. Mich
Jimmyblue I will check these areas on my next logs.What should my my commanded AFR be at start up?I dont want to run it to lean.Also How does Afterstart enrichment Figure itself into the picture and How long does it stay added?Ok lets Hypathetically say I am at a map of 45 KPA at 68 ect which is 1.15 so this makes me at 14.62857 Divided by 1.15=12.72 now we have an afterstart enrichment of .25 How does this figure in?I have exaust Leaks so my WB says 18.5 AFR..Thanks
Last edited by Pro Mouse; Sep 16, 2007 at 09:50 AM. Reason: I Left out info
My understanding is that afterstart adds to open loop EQ so
1.15+0.25 = 1.4 -> 10.5:1 AFR. Kind of chubby. And that's if
you have no low-RPM mixture error (sounds like you can't tell
with the whacked wideband readings). I think you want your
EQ table to be lighter, even at cooler temps, up to the highest
idle MAP you see (plus bounce) you want a 1.0 EQ. Richer is
where you pick up a lot of "sogginess" and destabilize the RPM
- airflow loop.
1.15+0.25 = 1.4 -> 10.5:1 AFR. Kind of chubby. And that's if
you have no low-RPM mixture error (sounds like you can't tell
with the whacked wideband readings). I think you want your
EQ table to be lighter, even at cooler temps, up to the highest
idle MAP you see (plus bounce) you want a 1.0 EQ. Richer is
where you pick up a lot of "sogginess" and destabilize the RPM
- airflow loop.
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From: Shelby Twp. Mich
Thanks jimmyblue,Wow if that is the case this thing is so pig fat.Just like you said in your post above.Its no wonder why as soon as cooler air moves in it wont start....
