Cold start leans out till death

Nistune topics specific to the 6802 cpu

Moderator: Matt

Post Reply
harwood909
 

Posts: 9
Joined: Tue Jun 10, 2014 11:22 am

Cold start leans out till death

Post by harwood909 »

This is only during cold starts. I crank it over and it pops off beautifully, runs great for about 5 seconds and then the A/F just dives lean. I haven't been able to pinpoint at what temp this issue subsides. I have adjusted cold/warm cranking enrichment tables and they are identical to each other. I will attach the log I took of this happening. From what I can see (pretty novice opinion) there are no major changes to any of the data being logged that could cause this large of a lean surge.


Edit: I did some testing. It idles and cruises great with my K at 283 when warm. I adjusted it while cold starting it and was able to get it stoich with a K of around 443. Obviously I won't want to do that everytime I start it cold. I just am out of ideas as to what tables have affect on a cold, running, motor.

87 Z31
Innovate MTX-L
Holset Hx35
550cc injectors
Stock AFM
Attachments
Cold start leaning out (2).csv
(18.23 KiB) Downloaded 123 times
raddy
 

Posts: 167
Joined: Mon Mar 16, 2009 9:52 pm

Re: Cold start leans out till death

Post by raddy »

What about temp enrich table? As it start ok,crank values should be ok. If you improved it by k,same thing should be possible by altering temp enrich.values. You will get longer inj.pulsewidth for cold afr to make it more rich,without altering k. And check if temperature reported by ecu is matching reality.
harwood909
 

Posts: 9
Joined: Tue Jun 10, 2014 11:22 am

Re: Cold start leans out till death

Post by harwood909 »

I don't see a table labeled "Temp Enrich" exactly. Just "Enrich (Cold Crank)" and "Enrich (Warm Crank)"
harwood909
 

Posts: 9
Joined: Tue Jun 10, 2014 11:22 am

Re: Cold start leans out till death

Post by harwood909 »

I made some serious adjustments to the Cold & Warm Enrichment and I think I'm on the right track now.

I noticed today that when my temp got to 140 the car's idle smoothed out as if it switched to a different map. I haven't read anything about this situation anywhere. Maybe Matt can shed some light on the what is happening?
Matt
Site Admin
 

Posts: 8961
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: Cold start leans out till death

Post by Matt »

Those tables stop being used around 80 degC
Post Reply