idle high
 

hey guys how high should your car idle, i took it out today, its really cold outside, and the idle was really high, it was completly trimmed on the radio, but still idled really high till i turned it down on the engine. but im not sure how low to turn it ? another quicky here: if the weather is colder, should you richen or lean the needles ? and why ? i need to grasp this temp thing. thanks for any help

RE: idle high
 

its hard to say how high just keep it high enough to idle good so it doesnt stall. as for the weather when its cold you should richen the needles a bit cuz the air is thinner and causes engines to run lean.

RE: idle high
 

cool thanks, so cold=rich warm =lean

RE: idle high
 

Nope. Cool air is denser (opposite to thinner), THAT's why you richen, cos more air=need more fuel. same difference, cold=richen, as you said, just thought I'd enlighten as to the reason why...;)

That's why your idle is high on a cold day as well, 'cos the air is denser...

RE: idle high
 

Good advise. That's the first time I've seen it about temp issues....LOL..

RE: idle high
 

Colder air = more power because you get more fuel and air into the motor :D. When the air is cold and dense you get more air into the motor thus making it run lean... to compensate richen the high speed needle 1/8 at a time untill you get it where you want it. Hot air of corse is the opposite. Humidity also has something to do with it... the more humid it is the richer these motors run due to the extra water vapor in the air.

RE: idle high
 

BUT.There is always a BUT.
You should check your temps according to ambient temperature.
Say the ambient is 50 you shoyldn't run the engine more than 220(MAX).If the air is 80-90 then you can go up to 250.This is to make sure that the engine it's not lean.Cause an engine running at 250 and ambient at 50 means that it runs leaner than when it's at 80-90 ambient.
Confused you???:D

RE: idle high
 

Correct :). Colder ambient temps means colder running temps even with a lean mixture... of corse the cold air just cools the motor better. Never run a motor colder than 200 degrees... colder temps means less cylinder expansion which results in more engine wear. Never run these motors over 260 degrees because everytime you overheat them the sleve doesn't shrink back quite as far as it once did when cold (thats also why you have a harder time getting a sleve out of an overheated motor as compaired to a motor thats been ran correctly).

RE: idle high
 

This is a chart for the Air and fuel mixture.

RE: idle high
 

It's not that simple though.You have to take on acount the ambient temperature as is(heat), not only dense air ...!!

RE: idle high
 

Ambient temp is about 1% of your engine tunning chris. Unless you get snow or water on the head to cool it off.

RE: idle high
 

Yes i know,but i'm not talking about the fine tuning of the engine, but how the ambient affects the engines temps and how this can lead you to lean the engine more, cause you see low temps and you might think it's rich...[sm=thumbup.gif]

RE: idle high
 

Um, did you miss the temperature part of the chart??
It is that simple. The chart tells you which direction to go. Ambient tempeture will effect the tuning of any engine.
Granted ambient temperatures factor in, but when metal is 300 degrees, it's 300 degree regaudless of how it got that hot!

RE: idle high
 

NO NO NO!!
That's why it's not that simple,BECAUSE the chart is simple!!!:eek:
Anyway you can try and find out!!

RE: idle high
 

Dangerous rule that, Once you've got it runing nicely at a medium ambient temp think about plugs rather than twidling screws. If you keep leaning out, you WILL blow the lump. Plugs are rated for fuels and ambient temps, better to keep the lubrication constant and just get a plug of the correct temp range, so if it's cold out, you need a plug below #5.

The general system is low number eg #3 = hot plug and high number eg #8 is a cold plug. It all relates to the heat the filament retains after ignition so that it can ignite the next ignition, so obviously on a cold day the filament needs to hold more heat to ignite the colder mixture. There is the denser air arguement but that is irrelevant.