Thread: high idle and out of ideas, please help

Since the day I bought my Nx2000 it idles quite high when cold. 1500-1800 rpm is usual. When I warm up the engine, I need to really really warm it and I get somewhere close to base idle.

My mileage is really bad and of course I would like to get better mileage, but I post this question because my idle stays way too high with cold engine.

I replaced MAF, lambda, (second hand) but from a car that didnt have high idle.

I'm not sure what it could be or what to look for. Ignition is dead on and I also adjusted my idle screw in timing mode. The idle screw is all the way down.

I'm not aware of how the SR20 regulates its own idle or how it gets extra fuel when cold, the mileage is below 10km to the liter with very proper driving (1:22) and the sparkplugs look like lean burn.

Also the car is showing white smoke at idle and all the signs of bad fuel consumption, please help me out, I'm out of ideas and want to check everything on the car anyway.

lol, i do believe the white smoke is steam or something.. like when its cold outside and you exhale.. same kind of effect.. did it JUST start gettin cold around there?

my car idles at 1500-1800 when its really really cold out side.. or like 1200-1500 not to mention my car takes 15 mins to warm up thats just the way the engine warms up, if it was idling at 800 on a cold day when it just started it would have a hard time staying running or would take forever to warm up.


if you just get in the car turn it on an go, that would explain your high mileage possibly.. but milage should be normal when its fully warmed up..

always warm your car up properly before drivin it, they last longer that way

When you say that you replaced "lambda," are you meaning you replaced the O2 sensor? If not, you might want to check that.

Also, you might think about replacing the temp sensor that tells the ECU what the water temp in the engine is. If this is faulty, your ECU could be getting confused. There are 2 sensors, so make sure that you replace the correct one.

When you adjust your base idle (in timing mode) are you able to get it set to spec?

It is normal for the engine to idle high when cold. Does it return to 700-800 rpm after the car is warmed up? What mods are done to your engine? Did you try changing simple things such as the air filter, fuel filter? Did you check to see if your throttle cable is sticking Sometimes that happens if it is adjusted too tight. If your car is continuously idling high your going to get bad fuel milage of course it all adds up. The white smoke is condinsation built up in your exhaust stream from the natural prossess from your Cat converter..It converts carbondioxide to water vapor.

The high idle is already too high with a cold engine and doesnt go lower very quick. If it idles that high it should go to lower rpm pretty quick, like in seconds.

What I don't understand is that when the engine is really warm I can get it somewhere between 850 - 900 rpm if I really want that. At the moment I've set the idle a bit higher because that just gives me the idea it's better/I like.

I'm trying to make the car bone stock, already put the stock filter on and I'm about to even get that little hose between the ''Nissan CAI'' and the filter box.

What I'm puzzled on is that the sparkplugs look like this: SP23.JPG and no matter how proper I drive it, I get same fuel economy on highways and city driving and that just can't be right.

I'll measure the lambda tomorrow, I expect it to be not in great shape but that should only be a reason for the fuel economy, not the high idle.

I must say, the car can smell like fuel so that's not good. I'm not sure how bad it throws out fuel but even car's with a reasonable gas consumption can smell like fuel. I'm pretty sure it throws out unburnt full but why do my sparkplugs show lean burn? I would expect black deposits on the plugs.

To make it more complicated, I also closed the intake at the airfilterbox with some leather gloves that won't pass air and I didn't feel underpressure nor the engine shutting down, idle didn't lower and the engine kept running like nothing happened.

What I really would like to learn here is how the SR20 can suck in air somewhere when something is not right and still behave like cold, high rpm, warm, proper rpm.

I also pulled the Auto Choke fuse and the Engine Cont. fuse. I can understand with too much fuel It won't miss the Auto Choke fuse but why the car is behaving the same when I pull Engine Cont.?

Also, what the heck is a Bulb Check?

heh, im lost man :P

AICV swap didn't help, I pulled lambda connector instead of measuring it and watch my fuel gauge

I'm hoping to swap AAC tomorrow and my Consult cable came in today

btw, I tried to check the vacuum under the car as far as it would let me on the parkinglot and couldn't find anything wrong. I noticed by removing AICV and letting the tubing loose, car won't start.

i too have had idle issues, i am running the aem ems, and even trying to use nkown good idle calibrations cant get my idle to go down , to idle at a lower engine speed. im at around 1200, which isnt bad ,but i just cant get mine down either, i havent tried any different iacvs but i have tried numerous aac valves i donno

I notice I'm posting my findings in 2 several topics..

But I tried Free Conzult yesterday, it has the neato Base Idle Adjustment option.

And weird weird *The Twilight Zone* with a still pretty cold engine, idling 1200, hitting that button makes it go 850!

So if it can do that, why it doesn't do that always? Problem solved! But I adjusted my idle screw and indeed get a somewhat lower idle, however the engine was still warming up of course.

Next day, with stone cold engine, starts and stall, so I openend the idle screw some more and presto my high idle is back. Now I do have a broken Parking/Neutral sensor, the lambda behaves like having a bad connection and while it was working at its best wasnt very good working and also the Coolfan Hi and Low started blinking erratically into weirdness.

I'm gonna swap the AAC but that ain't gonna help