Why are the RPMs high when the car first starts?
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Why are the RPMs high when the car first starts?
I have been around this site for awhile and I have learned alot. One question that I have tho, is why the RPMs are high when you start your car in the morning and what makes them drop when the car is warm. Thanks!
Rob
Rob
Strictly emissions. The fuel burns more completely/efficiently in the combustion chamber the closer to operating tempurature it is (around 202 degrees F). So the ECU monitors the water tempurature, adjusts the idle accordingly so the car will warm up quickly, thereby reducing harmful emissions faster. Hope this helps!
Wow it's 7:02 am
Wow it's 7:02 am
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From: Tampa, FL
Rep Power: 0 i didn't know that either but thx mango 
and if u guys have never noticed, while your car is on and parked, pump the brake a little bit and you will notice the rev's go up a smidgen (go up and down with each pump of the brake). i never noticed that either until i was at a stoplight in my friend's itr and he showed me.
just a stupid thing i guess
and if u guys have never noticed, while your car is on and parked, pump the brake a little bit and you will notice the rev's go up a smidgen (go up and down with each pump of the brake). i never noticed that either until i was at a stoplight in my friend's itr and he showed me.
just a stupid thing i guess
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Rep Power: 412 Thanks Mango. that helped alot. Also if you hit the clutch, the RPMS go up too! all this stuff I have to learn.
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[hr]Originally posted by: robbclark1
Thanks Mango. that helped alot. Also if you hit the clutch, the RPMS go up too! all this stuff I have to learn.[hr]
[hr]Originally posted by: robbclark1
Thanks Mango. that helped alot. Also if you hit the clutch, the RPMS go up too! all this stuff I have to learn.[hr]
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[hr]Originally posted by: Grey
That's 'cause the engine no longer has any load on it. Yep. You can initiate a drift like this. Go into the turn, turn hard and depress the clutch. It's called clutch kick. [IMG]i/expressions/demon.gif[/IMG][hr]
[hr]Originally posted by: Grey
Quote
[hr]Originally posted by: robbclark1
Thanks Mango. that helped alot. Also if you hit the clutch, the RPMS go up too! all this stuff I have to learn.[hr]
[hr]Originally posted by: robbclark1
Thanks Mango. that helped alot. Also if you hit the clutch, the RPMS go up too! all this stuff I have to learn.[hr]
[IMG]i/expressions/demon.gif[/IMG]
<ahem> with no traffic of course
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From: GARDENA, California, US
Rep Power: 0 it's cause you need a rich mixture to start the car and the pcm makes up for the mixture with a lean command until the coils and windings get warm enough to when the car can idle normally (closed loop)... and yes it is emissions related... im a smog technician/ mechanic =)
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From: Ontario, Canada
Rep Power: 0 Are you guys nuts? SInce the dawn of the car engines always Idel high when they are cold. This used to be done by a nifty inventon known as a CHOKE... now however itis controlled by the vehicle's ECU.
The purpose of the high idle is to allow the vehicle to reach it's proper operating temperature sooner. Thus creating the desired conditions for the emissions control system to do it's job.
The emissions control systems on a vehicle do not... and I repeat DO NOT operate worth beans before the vehicle has reached the designed operating temperature.
In short... all vehicles do it when they are cold and it is a good thing they do. (just incase any of you were still confused.)
Hope this helps!
[IMG]i/expressions/face-icon-small-smile.gif[/IMG]
The purpose of the high idle is to allow the vehicle to reach it's proper operating temperature sooner. Thus creating the desired conditions for the emissions control system to do it's job.
The emissions control systems on a vehicle do not... and I repeat DO NOT operate worth beans before the vehicle has reached the designed operating temperature.
In short... all vehicles do it when they are cold and it is a good thing they do. (just incase any of you were still confused.)
Hope this helps!
[IMG]i/expressions/face-icon-small-smile.gif[/IMG]
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