mike2016 Posted March 23, 2021 Report Share Posted March 23, 2021 I've been messing with this startup issue for days.... i can't seem to figure out why. it was never an issue on the G4+. I tried several different settings - old g4+ cold start, Link basemap cold start, setting from another tuner. 3 different settings. same thing. it's completely random. sometimes it starts up perfectly fine, next day it would start then stall (1 bang then dies immediately). same for warm/hot engine startup. if it doesn't start properly on the first try, it would flood the engine and will take a lot of cranking to start it up again. and it starts up super rich at 0.65-0.68 lambda i did 4 different startup logs today. the 1st one shows lambda at 1.3 at cranking, but the other 3 are close to target. the 1st start up almost failed but it started. the other 3 are perfect start ups. I tried bigger "pre-crank prime" and lower "crank + post enrich", or lower "pre crank" and bigger "crank + post enrich". similar results. 1st one seems to have less failed starts. PC Datalog - 2021-03-22 6;03;34 pm Cold Start 1.llgx PC Datalog - 2021-03-22 6;05;49 pm Cold Start 2.llgx PC Datalog - 2021-03-22 6;10;15 pm Cold start 3.llgx PC Datalog - 2021-03-22 6;17;46 pm Cold Start 4.llgx Quote Link to comment Share on other sites More sharing options...
mike2016 Posted March 23, 2021 Author Report Share Posted March 23, 2021 I also tried taking out more fuel from pre-crank or crank enrich, one at a time... similar results. it's very inconsistent. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted March 23, 2021 Report Share Posted March 23, 2021 Attach a copy of your tune too please Quote Link to comment Share on other sites More sharing options...
mike2016 Posted March 23, 2021 Author Report Share Posted March 23, 2021 1 hour ago, Vaughan said: Attach a copy of your tune too please here's a dropbox link. it won't let me attach anymore files... https://www.dropbox.com/s/pjwr7ybqojptado/13 - fuel map adjust and cold start adjust.pclx?dl=0 Quote Link to comment Share on other sites More sharing options...
Vaughan Posted March 24, 2021 Report Share Posted March 24, 2021 I can't spot anything straight off the bat and although I have a similar engine setup (RB30 with S2 25de head and a 24-1 trigger kit) I haven't actually tuned my main fuel table or warmup enrichment properly yet so issues are to be expected with my setup. As a side note your wall wetting compensation is massive, I typically have Asynch inj on, a 5% wall wetting compensation and no accel enrichment. Quote Link to comment Share on other sites More sharing options...
mike2016 Posted March 24, 2021 Author Report Share Posted March 24, 2021 i know... if any setting will start the car, it should do it every time with the same result. on the same setting, one day i can go on without any issue. then next day, first start up fails and floods the engine. i didn't touch accel enrich/wall wetting yet, as i want to get the start up issue sorted first. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 24, 2021 Report Share Posted March 24, 2021 I would definitely zero out the wall wetting comp for a start, Im not sure if that code is locked out at start-up or not but if not it definitely has potential to cause highly variable injector PW so I would take that out of the equation. Quote Link to comment Share on other sites More sharing options...
mike2016 Posted March 24, 2021 Author Report Share Posted March 24, 2021 got it! i'll give that a try and report back Quote Link to comment Share on other sites More sharing options...
mike2016 Posted March 25, 2021 Author Report Share Posted March 25, 2021 changed wall wetting comp to 0, and enabled asynch inj 0.5ms. no more failed starts! i think a lockout setting for wall wetting comp should be added dx4picco 1 Quote Link to comment Share on other sites More sharing options...
0x33 Posted April 1, 2021 Report Share Posted April 1, 2021 Just to add to this thread. Been having hot start issues with wall wetting enabled on RB26 and 2JZ, usually between 2-5%. Was scratching my head as to why it was causing issues, but remembered this thead and disabled wall wetting and starts every time. Still not as fast as G4+, seems like it takes one engine cycle longer. Can the documentation for wall wetting and asynch injection be improved whilst you are looking at this. Maybe give some worked examples, hard to understand the balance between Async, wall wetting and accel enrichment. dx4picco 1 Quote Link to comment Share on other sites More sharing options...
dx4picco Posted April 1, 2021 Report Share Posted April 1, 2021 42 minutes ago, 0x33 said: Can the documentation for wall wetting and asynch injection be improved whilst you are looking at this. Maybe give some worked examples, hard to understand the balance between Async, wall wetting and accel enrichment. I would second this request! Quote Link to comment Share on other sites More sharing options...
dx4picco Posted April 3, 2021 Report Share Posted April 3, 2021 As heads up, I've also tested with wall wetting off, and car stats now like a charm like my other experiences with G4+, so that definetly came from that 0x33 1 Quote Link to comment Share on other sites More sharing options...
mike2016 Posted April 9, 2021 Author Report Share Posted April 9, 2021 yep. since wall wetting off, start up has been consistent and never failed once. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted April 21, 2021 Report Share Posted April 21, 2021 As a note on this it looks like you don't need anywhere near as much first crank prime when you are using wall wetting as they end up doing similar things to each other when starting the engine. Quote Link to comment Share on other sites More sharing options...
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