rough idle on hot startup
#1
rough idle on hot startup
ive noticed an issue with my tune in that if im out running errands and I shut the car off and then go to start it up soon after I will get a very rough and low (between 500-750 rpm) idle. once I increase the rpms a little bit (up to 1500 or so) the idle will reset itself and go back to 950 rpms.
does anyone know what i should adjust in the rom to correct this? my idle is set to 950 at operating engine temps both in neutral and in drive.
my injectors are scaled correctly, my LTFT's are within +- 5%
thanks
does anyone know what i should adjust in the rom to correct this? my idle is set to 950 at operating engine temps both in neutral and in drive.
my injectors are scaled correctly, my LTFT's are within +- 5%
thanks
#2
im having the same issue. and my AFR are bouncing around between 12-19.0. but when i tap the throttle a bit, it stays at 850(where i set it) and between 14.7-15.0
any insight will help me too.
any insight will help me too.
#4
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Join Date: May 2005
Location: Santa Monica, CA
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Pay attention to what the wideband gauge is reading while it's running rough. If it's running very lean, but other than a hot re-start the car runs 14-15 at idle, you're having a hot start enrichment issue.
Are you running MAF or speed density? This symptom is a known issue with the way the Speed Density implementation was handled. The IAT sensor gets artifically heatsoaked in a situation like this and commands the ECU to pull out fuel causing it to read lean until the IATs drop down, or until the car enters closed loop and the fuel trims help in the meantime. If it's a MAF car, the post-cranking fuel enrichment tables should help deal with this. It should help with SD too as a "bandaid".
Are you running MAF or speed density? This symptom is a known issue with the way the Speed Density implementation was handled. The IAT sensor gets artifically heatsoaked in a situation like this and commands the ECU to pull out fuel causing it to read lean until the IATs drop down, or until the car enters closed loop and the fuel trims help in the meantime. If it's a MAF car, the post-cranking fuel enrichment tables should help deal with this. It should help with SD too as a "bandaid".
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