richardpalinkas Posted August 6, 2019 Share Posted August 6, 2019 What have people here done to get that aggressive cold start idle, such as m spec BMW's, which have high idle rpm and retarded timing? I've played around with some idle air multipliers but would like it more aggressive if possible Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted August 7, 2019 Share Posted August 7, 2019 They actually do have a fairly aggressive cold start idle from the factory already. But to answer your question the car uses the following maps for idle timing when cold. You can put anything you want in there. They will usually use about -5 degrees but you could go much more retarded to warm the car up faster if you want. Regarding idle speed you can simply increase one of these tables to increase the cold start idle speed. ECT is probably the best one to use as that way it will only do it when cold. Quote Link to comment Share on other sites More sharing options...
richardpalinkas Posted September 15, 2019 Author Share Posted September 15, 2019 Sweet thanks. In regards to idle spark timing, do most tuners leave them at the factory settings of 60deg commanded spark or adjust it to something else, like 17 deg? Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted September 15, 2019 Share Posted September 15, 2019 Those tables are not used from what I can see. Quote Link to comment Share on other sites More sharing options...
richardpalinkas Posted September 15, 2019 Author Share Posted September 15, 2019 Even when the engine is at operating temp? What table controls idle spark? Quote Link to comment Share on other sites More sharing options...
Sam Posted September 15, 2019 Share Posted September 15, 2019 Spark is used to control idle rpm. If you have a vacuum leak your spark will drop to try and maintain you desired idle rpm. So your idle spark will vary to maintain your desired idle rpm. Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted September 16, 2019 Share Posted September 16, 2019 It is done based off a PID controller. You can modify the gain in this table. auF11706 Muliplier as a function of load on spark feedback gain_ fnspkfbs_gain. If you set it to 5000 for fun you'll see your spark flick between MBT and min spark clip repeatably. Good for a pseudo ghost cam. if you set it to 0 it will just run MBT timing and you'll have a high idle and if it starts to stall it won't catch it in time. Quote Link to comment Share on other sites More sharing options...
BeerTurbo Posted June 18, 2020 Share Posted June 18, 2020 My shitter had a slow start and a bit of a stutter on idle... I used the base idle fuel map to add a fair bit more fuel, the std falcon map leans out quite quickly. well compared to nissans im used to. Used the idle adder with ECT to add 100 idle untill around 60 deg. Car started much nicer and was happyier...still had an idle stumble. > battery was bad - changed to new battery and car started instantly and the stumble/miss is gone. i know this is no help to your bwm start, but i figgure its helpfull note that making it richer and idle higher is prob not a bad idea. Quote Link to comment Share on other sites More sharing options...
richardpalinkas Posted July 10, 2020 Author Share Posted July 10, 2020 Just to update, if you modify the idle spark tables (normally have values of 60deg) it will change the idle spark value. Say if you set it to 10 deg, it will command 10 deg and adjust throttle to keep it at 10 deg idle spark 1 Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted July 15, 2020 Share Posted July 15, 2020 Yeah the idle spark will take the minimum of that table or MBT. This is a good way to lower the spark idle without modifying the MBT table. Quote Link to comment Share on other sites More sharing options...
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