Cold start

iaredam · Post by **iaredam** » Mon Dec 08, 2008 3:59 am

I have a U13 with a type 3 board, and am wondering what each of the cold start maps actually do. There's a Cold Start Main, Cold Start Secondary, Cold Start Throttle, and a Cold Start Timing Advance.
I figure that the Throttle map adds more fuel and the Timing Advance advances timing while it's starting when cold. I'm just not to certain exactly what the Main and Secondary Cold Start maps do...

What's happening is when I start my car up and it's cold out, it will run extremely rich for ~15 seconds or so and sometimes it will want to die unless I give it some throttle. I'm guessing that when I changed the 270cc injectors to 550s I should have changed either the Cold Start Main or possibly the Cold Start Secondary and decreased the values by a percentage.

Any input would be appreciated.
Thanks

Matt · Post by **Matt** » Tue Dec 23, 2008 12:04 pm

let me have a look into it on the bench. I've got the 16 bit hardware maptracing working now and had a few questions like this. So I can see which tables get accessed and when

Documenting as I go and will post something up very soon

iaredam · Post by **iaredam** » Thu Dec 25, 2008 8:08 am

Good deal, I'm not sure if this will be useful or not since it's for 93 & 94 U13s: http://www.nissanclub.com/forums/ecm-ec ... esses.html

Matt · Post by **Matt** » Fri Dec 26, 2008 12:14 am

its all good. I can cross reference a lot of routines between different ECUs since code bases are similar. Thanks for posting that through

iaredam · Post by **iaredam** » Fri Jan 02, 2009 9:10 am

I ended up adding in these entries:
CRANK_TIMING,&HE310,16,1,16,1,Engine Cranking Additional Enrichment
WARM_START_ENRICH,&HE320,16,1,16,1,Engine Cranking Inj Pulsewidth
AS_ENRICH,&HE330,16,1,16,1,Engine Cranking Pulse Offset

I don't know the proper syntax for the table names, so I just chose ones that I found in other address files. I ended up decreasing the values by roughly half, and that has stopped the issue of overfueling while cold starting. I am still getting a lean idle, but I believe the cold start main map might just need to be adjusted.

Matt · Post by **Matt** » Fri Jan 02, 2009 10:44 pm

those ones came from what calum found (and same as those in the U13 file) so sounds like you've got it right