DR_EviL Posted July 10, 2019 Report Share Posted July 10, 2019 Stepper is working correctly, higher numbers make lower idle rpms. I have the cranking steps number as high as possible (100) but the engine still revs too high each time it starts. Quote Link to comment Share on other sites More sharing options...
Simon Posted July 11, 2019 Report Share Posted July 11, 2019 Pull the start up steps to a smaller number ( on these a lower number will give a lower idle increase) Quote Link to comment Share on other sites More sharing options...
DR_EviL Posted July 11, 2019 Author Report Share Posted July 11, 2019 I tried a lower number first and it made the problem worse. I will test again. Quote Link to comment Share on other sites More sharing options...
JMP Posted July 11, 2019 Report Share Posted July 11, 2019 I've seen 2J's with the stepper wired backwards before, so rpm increased as the idle table numbers were reduced Quote Link to comment Share on other sites More sharing options...
DR_EviL Posted July 11, 2019 Author Report Share Posted July 11, 2019 The car arrived with increasing numbers in the base position table at higher temperatures, a bigger number makes a lower idle. I have never had a car where bigger numbers made lower idle but i'm not familiar with stepper motors, most things I tune have pwm valves or nothing at all. This seemed wrong to me, but the help file says, "If you find that increasing the number in the idle base position table causes the idle to increase then the stepper motor is wired in reverse" Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 11, 2019 Report Share Posted July 11, 2019 To clarify, with a stepper motor a larger base position number means less air/lower idle speed. So it sounds like you have that part right. The "start up step" subtracts from the base position number so it works more like how you expect it to - a larger start up step gives more air. It sounds more like maybe the stepper reset is not happening correctly on power down, is this a supra plug-in ecu or a wire-in ecu? Perhaps you can do a short PC log of a start up so we have some data, - turn ignition on, start logger, then start engine. Quote Link to comment Share on other sites More sharing options...
DR_EviL Posted July 11, 2019 Author Report Share Posted July 11, 2019 This is a Plug in ECU. Here is a log of a fully warmed up startup. Log 2019-07-11 12;24;56 pm.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 12, 2019 Report Share Posted July 12, 2019 Can you do another log with the start up step set to zero. For some reason in that log there is a whole chuck of data missing, it jumps straight from 200RPM to 1800RPM. Also a copy of your tune would be helpful. Quote Link to comment Share on other sites More sharing options...
DR_EviL Posted July 18, 2019 Author Report Share Posted July 18, 2019 On 7/12/2019 at 9:16 AM, Adamw said: Can you do another log with the start up step set to zero. For some reason in that log there is a whole chuck of data missing, it jumps straight from 200RPM to 1800RPM. Also a copy of your tune would be helpful. Thanks With the step at 0 it struggled to start, now set at 25 tapering down to 18 when hot. This solved the issue for a few days. Now on the first cold start of the day the idle sticks 1000rpm above my open loop target throughout the whole warmup, a key cycle cures the problem. Quote Link to comment Share on other sites More sharing options...
cj Posted July 19, 2019 Report Share Posted July 19, 2019 Can you do a log of this happening + post your map? it sounds like you are exceeding one of the parameters that needs to be met to let one of the idle systems kick in. Maybe ignition idle control never kicks in and your timing values in the main igntition table are too high for the revs to drop. Quote Link to comment Share on other sites More sharing options...
DR_EviL Posted July 19, 2019 Author Report Share Posted July 19, 2019 10 hours ago, cj said: Can you do a log of this happening + post your map? it sounds like you are exceeding one of the parameters that needs to be met to let one of the idle systems kick in. Maybe ignition idle control never kicks in and your timing values in the main igntition table are too high for the revs to drop. Thanks This is open loop on the icv and the ignition timing. It only started after the customer did some wiring in the bay. it only did it twice then went back to normal. Quote Link to comment Share on other sites More sharing options...
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