Weird idle issue- MS1V3
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I'm having a weird idle issue. I start up the car, and it idles pretty well at ~850 RPM. AFR's are at about 14.7-14.9, vacuum is good, timing is at 17* and CLT is at 200*F.
After about three minutes or so of idling, the car will rev to about 2000 RPM and then go back to 850 over and over again. It will do this endlessly. CLT is still the same as before.
Any ideas? Car is a Greddy'ed 1.6 with stock injectors, though I have the waste gate arm disconnected at the moment.
After about three minutes or so of idling, the car will rev to about 2000 RPM and then go back to 850 over and over again. It will do this endlessly. CLT is still the same as before.
Any ideas? Car is a Greddy'ed 1.6 with stock injectors, though I have the waste gate arm disconnected at the moment.
![](https://www.miataturbo.net/attachments/megasquirt-18/76524d1368463490-weird-idle-issue-ms1v3-datalog.png)
Last edited by albertogti117; 05-13-2013 at 12:46 PM. Reason: Attached datalog and MSQ
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check your idle dc over that period you logged - i bet it is cycling up and down to make this happen. i had the same on mine and it didn't make any sense. it was a while ago now but i think i fixed it (or at least managed a work-around) switching over to warm-up only, and back to closed loop again. for some reason my MS just got itself in a mess.
of course, you do need to check your closed loop idle settings are sensible
of course, you do need to check your closed loop idle settings are sensible
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Skinny, I did as you said and logged the idle DC when the event happens. It pings to a value of 63 and then goes back down to 18. When switched to warmup only, the the issue doesn't happen so it's definitely a problem with my closed-loop settings. Here's a log:
![](https://www.miataturbo.net/attachments/megasquirt-18/76619d1368551433-weird-idle-issue-ms1v3-idle.png)
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well look at the value it's giving in your logs, the input still floats around and goes crazy. Could have an effect, consdiering you have a TPS ADC threshold of 85 and your TPS is reporting 19500ADC in that log...
but im much more curious about seeing the AFRs.
but im much more curious about seeing the AFRs.
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