there is this thread running at MSextra, but none of the MS guys seems to really care about the problem.
I know I am not the only one (especially of the 99/00 Miata guys - Reverant etc.) who experiences these hickups at light throttle conditions.
I made a lot of logs and screenshots...
Here are some screens -
Again - you can see the changes in AFR, when nothing else really changes. Not the TP, not the TPSdot, no change in any of the PWs.
I can reproduce it mostly in slight uphill drive with steady throttle at ~15-20% and MAP being just below boost (~90kPa)
Last week I might have made a new step to see what causes the hickups...
I had used Tuner Studio with an Laptop before with an serial to usb adapter. There were some problems with that in the past so the data rate was set to 10 frames per second. (And I forgot about that...)
As I am using an In-Car PC now with an direct serial connection I set the data rate to max now and did some new logs.
Here is a screenshot of the hickup with the new data rate:
As you can see in the screenshot of the log - the RPM starts to fluctuate wildly just before the hickup-event.
(Which you can see in the AFR line).
So what could cause this?
I have no sync losses. Which I would suspect to see if the CAS or CAM input would drop out...
My RPM lag is set fairly high(low?) at 85. Should I try a lag factor closer to 50 or 60?
Thanks for your input. I hope to get rid of this annoying stumbles....
And I think the whole 99/00 crowd would appreciate it...