Wierd Idle

[Temjin]

First of all I live in Cleveland. At this point there is about an inch of snow on the ground and its still coming down. The temperature is about 10 degrees. Its kinda hard to start the car for the first time of the day. When I do, it idles kinda rough, but after about 5 minutes its better but not the best. Then after about 20 mins of driving its fine. What do you guys think? Could it just be the weather?

[slw240sx]

the car is in a closed loop operation it dumps extra fuel into the mix to make the car idle fast till the car is warmed up. once the coolant temp reaches a certain point it triggers a coolant temp sensor that runs to the ECU and tells it to run in open loop and provide the standard fuel mixture.

CAs hate i repeat hate cold weather, you will prob have to start it and hold it at a higher then normal idle for a few mins then it will start to settle down a bit, also let the thing warm up 20 mins or so before really driving agressively.

also please check your ECU i think i might have left it in a test mode in the hurry of getting it finished.

[paul_s13]

I'd agree with the ecu coolant temp sensor, the cold idle should be about 1200rpm and drop to 800rpm when warm, I never had any probs with cold starting or idle, the only thing that I found was that CA's get a clattery top end for a few seconds when its really cold.

[gani]

mine does the same thing like first thing in the morning it will idle high but after some driving its back to normal. if its during the day it will start up fine with nice idle.

[float_6969]

Well figure this one out.... My problem is completely temperature (outside) based. If it's any colder than about 40* when I go to start it, it won't stay running. It will idle up to about 1200-1400 and then it sputters out and dies. Then I have to wait a couple of seconds and try it again. The colder it is, the more times I have to do it till it will stay running. Got any ideas?

[slw240sx]

his will do the same thing, so did mine when i had it out in the winter, check your plug gaps. also your prob not geting as many crank amps out of the battery , on top of the oil being very cold and sludgier it can slow cranking, all this combinded prob leads to making the starting system work hard till everything is warmed up, (pulling most of this out of my *** as we go, but its possible, i think)

start the car hold the pedal down at 1200-2000 rpm let it high idle for a few mins. it might have to do with the MAF not being able to correctly read the air temps at first and flooding it,

but like ive been sayin these motors absolutely hate the cold weather, your flordia guys are lucky! !

[float_6969]

I can't touch the throttle or it dies...

[paul_s13]

Try checking the throttle position sensor or the idle switch, it could be playing up when the ecu is in coldstart mode.

I never had any probs and its always fecking cold here, the only funny noises I had was a bit of piston slap before the forged pistons expanded.

[float_6969]

TPS hasn't been checked(not sure how and I have pulled out the FSM to check) and the idle swich is closed like it supposed to be.