High Idle - Cold Start Warmup

[EmersonHart13]

Anybody familiar with how are cars are programmed to handle cold start warm ups. My car tends to idle at about 1K when it is cold and stays there it seems until the car goes to Open Loop, aka fully warmed up. I can understand the high idle when it is really cold, but this morning it was about 30, note I keep my car in the garage as well, and I was at high idle for most of my 8 mile drive to work.

Thoughts?

Thanks,

John

Also posted: http://www.ls1tech.com/forums/ls4-fr...rt-warmup.html

[ilikeMTB999]

Mine idles at 1800rpms when cold

[EmersonHart13]

But for how long....? My car has always done it, just seems to like doing it more often or for longer this winter.

[ilikeMTB999]

If I blip the throttle it'll come down to around a 1000. Then once the needle starts moving it'll idle at 800 like normal.

I can back outa the drive way an make it about a mile before having to use the throttle to leave a stop.


Just realized this was lsx country. That I do not have

[EmersonHart13]

LOL, I know you do not.

[Runtz52]

i have a V8 so i meet part of the requirements for the lsx sections, idk what my high idle is but after i rev it real quick it drops, u may want to try that

[ilikeMTB999]

You're carbed. A bit different.

Emerson you could change the table for startup/ warm up in closed loop. since your commute is so short you'd probably get better mpg but I'd drive carefully.

[EmersonHart13]

I don't have HP Tuners, I want it but 500 bones is hard to stomach... And then there is the laptop.

Interestingly enough on the way home it dropped the idle after just a few miles. I think it keeps the high idle longer when the car sits for longer. I didn't drive all weekend so the car just sat in the garage. I am going to see what it does in the morning.

[smug_GXP]

My GXP seems to do about that same thing. The longer the car sits the colder it is and the longer it will high idle. I use my remote start to let the car warm up when ever I can.

[Csurane24]

I wouldn't be worried about it all. My car does it for a good 10 minutes in the winter, granted I only start it once a month it stays high for a while. Once it gets into it's running temp it will be fine.

Video of first start up with new exhaust. I have a cam and you can't even tell.


http://www.youtube.com/watch?v=_Os0A7voJZo

[ilikeMTB999]

Letting your car warm up for extended periods of time can allow fuel to wash down your cylinders.

[EmersonHart13]

Yeah I try not to let it idle for more than 5 minutes, then drive it easy for the next five until I get to a main road. I never beat on it in the morning, heck I don't get past 3500 on the tach most mornings, and I never make it over 50, usually only up to 45 for a brief period...

[TransHed]

When I start my Trans Am up in the morning, my RPMs are usually at about 1000-1200. Drops to 800 when it warms up.

[ilikeMTB999]

Originally Posted by EmersonHart13

Yeah I try not to let it idle for more than 5 minutes, then drive it easy for the next five until I get to a main road. I never beat on it in the morning, heck I don't get past 3500 on the tach most mornings, and I never make it over 50, usually only up to 45 for a brief period...

Without hpt there's little you can do to help. Sounds very normal though.

[EmersonHart13]

I was more concerned with the, is it getting worse because there is some maintenance item I am missing. It sounds like no and it is just a crappy side effect of the severe cold/amount my car sits/short stop and go commute I have.

Thanks!

John

[Runtz52]

Originally Posted by Rufus Macarthur

You're carbed. A bit different.

Emerson you could change the table for startup/ warm up in closed loop. since your commute is so short you'd probably get better mpg but I'd drive carefully.

i know that but even with my lumina it did it as well

[EmersonHart13]

All my cars have done, but I don't remember them ever taking this long to drop.

[YoushallgoFo]

idk my 2000 z28 idles around 1000 in the morning too. I just let it sit for a while til it warms up. idk how long it takes for it to go down though, i'll keep an eye on it.

[Turk]

This is normal, car is programmed to do this so it warms up faster.

[EmersonHart13]

Okay so today I watched it again and it came down from 1k much faster than yesterday, and according to the car it was actually a few degrees colder today. Yesterday the car didn't come down from idling at 1k until the car was fully warmed up, today it came down after only warming up about halfway...

I think this is more related to the length of time the car sits. Which is strange to me.

[ilikeMTB999]

Length off time between startups? That would be odd.

[ktraver97ss]

I think your worrying about nothing. Im sure there are several factors that determine how quickly it gets up to operating temp, like ambiant air temp, temp in your garage, how much gas ur giving it upon startup, and prolly a bunch of other stuff. As long as its going back to a normal idle I wouldnt worry about it.

[TommyGloves]

Do you still have a scantool? You could check for Commanded RPMs to see what the computer is calling for at idle vs actual RPMs.

Also, if you are running the Defrost (ac compressor), that might contribute the difference in idle given the increase in load on the engine during the warm-up cycle.

Overall, it doesn't sound like a problem. Just my two cents.

[EmersonHart13]

Nope, I am tool less.... I wish I still had one.

I am not running the AC, though sometimes the auto climate control turns it on I have not see it on the past 2 days.

It many not be a problem, but I know it is not normal for the car to be idling at 100 rpms in 30 degree weather after driving almost 8 miles and running for 20 minutes. And as of right now the common denominator seemst to be length between starts.

For example, if the car is idling high but not fully warmed up and I turn it off then back on, after the restart the car will idle back below 1k at it's normal spot.

Weird, that is what it is, very weird.