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Title: Best timing for coldstart Post by: ericpaulyoung on June 10, 2015, 08:19:48 AM So I wanted to try something different and DD helped me out again to locate the starting timing maps. Previously I have been trying to adjust the start angle to see if it helped with the coldstart condition but I was using the maps in ZWMIN because there have "start and after start" maps in the function. But all this did was affect after start and the idle. So I moved to ZWSTT for start only maps.
So now here is the question. Not worrying about emissions, what is the best ignition advanced to guarantee starting? Audi sets this at 9.75° advance for a 200 RPM starting condition. I read some on the Internet that indicated top dead center was optimum for very low revolution started. So I try to reduce this to 2° and it did seem to start faster. What are others using, or what is the common knowledge for this? I have searched quite a bit, and surprisingly there is not much info on MBT for low rpm cold start conditions. People seem to concentrate on the most power up top instead when discussing MBT. Title: Re: Best timing for coldstart Post by: ericpaulyoung on June 10, 2015, 05:11:02 PM I just reduced the first column to zero and started even better. So it looks like the Internet was right. I also zeroed out the correction maps to force a zero advance. Started in two crank revolutions. ;) it looks like you can compensate for some fuel injector cold start issues by just correcting ignition timing a bit.
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