When i start up my 98 GT it shoots up to about 1600-1700 rpms and sits there for 45-60 seconds without me pressing the gas and then drops down to 600. why is it doing that?
high idle only at start
- Thread starter 98GTragtop
- Start date
nyuk98gt
15 Year Member
98GTragtop:
It does it because this is how the calibration is set up from the factory. There are start-up tables and timers that put the RPM up for a short period, probably to warm up the cat converters more quickly and minimize start-up emissions. You can get that initial RPM down if you change a few things in the tune. If you don't want to tune it out yourself (it takes some datalogging and time to get things just right), you can get a custom tune from a reputable tuner that does what you want and, as a bonus, can add a little HP/TQ, too. It only takes money, lol.
I don't know if the later models have the same start-up routine.
HTH,
Chris
It does it because this is how the calibration is set up from the factory. There are start-up tables and timers that put the RPM up for a short period, probably to warm up the cat converters more quickly and minimize start-up emissions. You can get that initial RPM down if you change a few things in the tune. If you don't want to tune it out yourself (it takes some datalogging and time to get things just right), you can get a custom tune from a reputable tuner that does what you want and, as a bonus, can add a little HP/TQ, too. It only takes money, lol.
I don't know if the later models have the same start-up routine.
HTH,
Chris
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