PWM IAC - Response After Startup Not As Expected

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goodysgotacuda
Helpful MS/Extra'er
Posts: 125
Joined: Sun Oct 05, 2014 5:07 pm

PWM IAC - Response After Startup Not As Expected

Post by goodysgotacuda »

Attached log and MSQ

My issue:
  • Cold starts are quite good, no complaint there
  • IAC runs up to 64% or so while cranking, engine starts, IAC goes to 29%ish immediately [why?]
  • While the IAC stays at 29%, the engine struggles at cold idle with no response from the IAC
  • Eventually the ECU enters closed loop idle, the IAC responds to the below target idle condition and ramps up
I am not sure how to get the IAC to do what I need it do -immediately- after startup through when closed loop conditions are met.

As you can see, the IAC shuts to 29% after about 1s of run time. It does not respond to the engine running for another 10s or so, which makes for a very poor running engine.
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1972 Plymouth 'Cuda - 5.7L Hemi w/T56 Magnum

MS3 Gold Box, TunerStudio MS/MegaLogViewerHD user
goodysgotacuda
Helpful MS/Extra'er
Posts: 125
Joined: Sun Oct 05, 2014 5:07 pm

Re: PWM IAC - Response After Startup Not As Expected

Post by goodysgotacuda »

29% looks like it may be coming from this table. I don't really understand what this table is doing for me during cold starts...Is the Y-axis supposed to be Coolant Temp?

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1972 Plymouth 'Cuda - 5.7L Hemi w/T56 Magnum

MS3 Gold Box, TunerStudio MS/MegaLogViewerHD user
goodysgotacuda
Helpful MS/Extra'er
Posts: 125
Joined: Sun Oct 05, 2014 5:07 pm

Re: PWM IAC - Response After Startup Not As Expected

Post by goodysgotacuda »

Figured out that long title for the y axis seems to just be CLT. It’d be a lot less confusing if it was labeled as such :)


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1972 Plymouth 'Cuda - 5.7L Hemi w/T56 Magnum

MS3 Gold Box, TunerStudio MS/MegaLogViewerHD user
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