mmaigret Posted September 6, 2020 Report Share Posted September 6, 2020 Hi All, I am having two issues on cold startup, idle hunting and poor throttle performance, which seem to vary across ambient air temperatures---where the "hunting" takes a longer time to smooth out in colder weather. I'm attaching a log and tune. The log was taken on a hot day (100F ambient), and the "hunting" lasted about 30 seconds where the idle RPM swings around 1k rpm and the car nearly stalls repeatedly on the downswing. As the car warms up the idle improves dramatically at first, then slowly at it reaches temperature and switches from 0.8 lambda to 1.0 lambda target. I'm new to tuning, and inherited the tune. My initial goal is to improve this idle condition. Things I've noticed are that "swings" in idle extend beyond the high end of the idle ignition compensation table, which also seems to have fairly asymmetric settings around target. I also noticed that the idle is set to open loop, with I believe closed loop idle deactivated. Another issue, which may or may not be related, is initial drivability after cold start. The car will basic bog and/or stall if not using the throttle incredibly delicately. Once the car reaches 1.0 lambda target, similar to above, it's generally fine. I believe something is going wrong during the warm-up time (~5 min) that essentially makes the car not want to take any throttle. Any help would be greatly appreciated. Thanks, Mike tune082620.pclr startup idle high ambient.llg Quote Link to comment Share on other sites More sharing options...
mmaigret Posted September 8, 2020 Author Report Share Posted September 8, 2020 I found this thread, which is very informative. I'm going to start there and see how things evolve. Thanks, Mike Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 8, 2020 Report Share Posted September 8, 2020 Sorry I missed your post. I have made some changes to your tune that should be a step in the right direction. Please update to the latest firmware also. Try this map and do us another log - I changed quite a bit so it may get worse before it gets better. It may need some further adjustments yet. I havent changed any fuel related stuff in this map. We will see if the throttle control is settled down first. The sudden change in lambda once it gets warm is due to the CLL reaching its enable temperature and turning on. tune082620 Idle tweeks.pclr Quote Link to comment Share on other sites More sharing options...
mmaigret Posted September 8, 2020 Author Report Share Posted September 8, 2020 Thanks Adam. Dumb question, but just want to be sure. I've been using the G4+ version of PCLink and firmware---I believe I'm using the latest versions of both. Should I instead be using the G4X versions, respectively? I have a R53 Mini with MiniLink plug-in ECU. Thanks again! Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 8, 2020 Report Share Posted September 8, 2020 You map says the firmware was 5.6.5, but I just looked at you log again and that shows 5.6.7 - so I assume you attached an old map from before you updated? Quote Link to comment Share on other sites More sharing options...
mmaigret Posted September 8, 2020 Author Report Share Posted September 8, 2020 Hi Adam, Yes, please forgive me I did update PCLink and firmware recently, and did not re-export the map/tune file. Apologies for the confusion. With regard to my broader question, is it correct that I should be using the G4+ versions of the software? I noticed that there is a R53 Mini base tune available in the PCLink G4X version? I would prefer to use the G4X version if possible; however, the tunes do not appear to be compatible between the two versions of PCLink. Thanks, Mike Quote Link to comment Share on other sites More sharing options...
Simon Posted September 8, 2020 Report Share Posted September 8, 2020 Correct the PC software used has to match the ECU generating G4+ for g4+ ecus Quote Link to comment Share on other sites More sharing options...
mmaigret Posted September 20, 2020 Author Report Share Posted September 20, 2020 Apologies for the delay. I tried the tune Adam provided and cold startup (80F ambient) worked much better than previously; I did not notice the violent swings in RPM as previously. I'm attaching a log. I did notice a near-stall and over-correction upon decelerating to a stop while pushing the clutch in, which I don't think is new behavior, but curious if any additional tweaks might improve this issue. Thanks! Mike tweaked idle 091920.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 20, 2020 Report Share Posted September 20, 2020 Most of the warm-up idle looks ok in that log. Can you try to get a log of this near stall effect. Quote Link to comment Share on other sites More sharing options...
mmaigret Posted September 26, 2020 Author Report Share Posted September 26, 2020 Thanks Adam. I logged a colder ambient startup tonight and noticed the unstable idle RPM during warmup again. One note is I tried to lower the idle target by 200rpm as I thought 1150 seemed higher than necessary. Also present in the log is idle hunt after engaging the clutch at speed, such as when coming to a stop. I did not notice any near stall behavior, but the idle rpm jumps from 1k up to 2k+ a few times before settling down once the car is stopped. Finally, I noticed at the end of the log that warm idle seemed Ok, but maybe not as good as I would expect; I noticed just turning the headlights on caused a noticeable temporary instability. I wouldn't think headlights would introduce significant alternator load on the engine, but maybe I'm underestimating. Sincerely appreciate all of your help thus far; please let me know what you think. -Mike tweaked idle 092520 950rpm.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 26, 2020 Report Share Posted September 26, 2020 Ok, it looks like you coast with the clutch in from quite a high speed, so I have changed the speed lockouts to see if that helps. The speed lock out and over-run fuel cut too close to idle looks like the cause of the oscillation when coming to a stop, so i've tried to improve that. Have also adjusted the cold proportional so hopefully that will fix the cold oscillation. Idletweeks2.0.pclr Quote Link to comment Share on other sites More sharing options...
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