[Diy_efi] Re: Dead cold rough idle FOLLOW-UP and thanks

[David M. Ingebretsen]

 Thanks for all the ideas and suggestions. It is idling much better now, not
perfect but much better.
 
I did two last major things, first I dropped my open loop AFR table values
between 37 deg C and "cold" to make it much richer. I dropped some values by
as much as 2. Second I looked at my volumetric efficiency tables at 800 RPM,
1200 RPM and 20 MAP and looked at the narrow average BLM's from my last
WinALDL tuning session. They were a little (not much) off so I tweaked them.
This morning, about 20 e.g. F or a bit colder, it started right up, idled
well and as I drove and stopped, the idle was just a bit bumpy but otherwise
fine.
 
Other things I also tweaked. I looked at the Cold AFR v. MAP table which
appears to be added to the cold open loop AFR. Most bins for my setup don't
change this table, however the Howell-Cold bin makes the values in this
table smaller making the final AFR richer than the other tables (which add
larger values to the AFR) (I think I have this right). So, I used this
Howell table. I also increased the temp at which I allow closed loop
operation to 65 deg C (not F). This also seemed to have a big effect on the
cold-warm idle and general operation. I use a heated O2 sensor but on this
inline 6, it seems to help to delay the closed loop until it is almost up to
operating temp. I tried playing with the decay tables, and timeout factors
(thanks Bill) but it didn't seem to make a big difference.
 
Anyway, the bottom line is it appears it was just setup way lean when
running cold. If anyone is interested in the bin, I can put it on the FTP
site or email it to you.
 
David M. Ingebretsen M.S., M.E.
Collision Forensics & Engineering, Inc.
2469 East Fort Union Boulevard, Suite #114
Salt Lake City, UT 84121
 
dingebre at 3dphysics.net
Work: 801 733-5458
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.diy-efi.org/pipermail/diy_efi/attachments/20060220/b4f2b4f3/attachment.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: unknown/unknown
Size: 2421 bytes
Desc: not available
Url : http://lists.diy-efi.org/pipermail/diy_efi/attachments/20060220/b4f2b4f3/attachment.bin