03 sportivo, idling funny

[tiet]

hi i was just wondering, my car is idling funny, when i warm up the car its fine, revs sit about 1100rpm.

after i drive it for a short time say 5mins and pull to the side revs drop and bounce from 100rpm to 800rpm

has anyone come across this problem or have any ideas?

and just to add i have no engine modifications at all

tiet.

[123R-Prozak]

Hey Tiet, hows it going man??

With ya car prob's, hows the condition of your throttle body?? Also can you hear any vacuum leaks? say when u turn the car off does it go shhh... or while the car is running..??

all vacuum hoses tight? Hows ya air filter? blocked.. ??

[KevO]

my mate had a similar problem on his vtec prelude.

found out the problem was with the petrol he used. switched to 98 octane and the problem stopped.

[the_random_hero]

my mate had a similar problem on his vtec prelude.

found out the problem was with the petrol he used. switched to 98 octane and the problem stopped.

Could be dodgy fuel, yes. Octane rating of fuel? I don't think so.

Do you mean 100-800rpm, or 1000-800 rpm? If it's 100-800, I'd start by checking for any vacuum leaks (although it's strange it doesn't occur on first starting up your car). The only thing I can think of is if your car has a BVSV valve or something similar which is controlled by coolant temperature - as your car warms up, the valve opens/closes and opens up a vacuum leak.

[tiet]

hey daniel lol

thanks for the comments everyone,

well, i don't hear no air leaks if thats what its suppose to sound like, my friend thought it was either an air leak or petrol, he checked the hoses though didn't find any leaks, and then he thought it was the petrol, i do recall walking behind the car after i've turned it off and it did smell funny.

with the throttle body, i think it should still be good, i am not sure how to check this,

and i meant 100~800rpm it feels like its trying to bog out.

i've always been running 98, i've been uses vortex since i bought the car, but decide to try bp ultimate for the last two weeks, idle started playing up on the second week of bp ultimate

Edited February 25, 2009 by tiet

[SuperDave]

and i meant 100~800rpm it feels like its trying to bog out.

Does it idle hunt during this? Is the AC on or off?

[KevO]

lols well i guess theres one thing to do.

use up the bp petrol and fill up with vortex and see how it goes...

[tiet]

and i meant 100~800rpm it feels like its trying to bog out.

Does it idle hunt during this? Is the AC on or off?

idle hunt?

no the ac is not on

[Hiro]

and i meant 100~800rpm it feels like its trying to bog out.

Does it idle hunt during this? Is the AC on or off?

idle hunt?

Did the idle speed jump up and down like it was almost stalling, or unstable and constantly switching between pre-set levels (like an auto transmission "hunting" when the car goes up a hill, and the tranny constantly swaps between two gears because it can't choose between them)

I'd be having a look at whatever kind of ISCV you have (usually a valve block on the under/side of the throttle body, controls idle speed depending on certain conditions such as cold engine, air conditioning, power-steering being switched on etc etc). The ISCV screwing up is a common cause on most EFI cars for a hunting or unstable idle.

[SQU-47N]

Had this same problem in my old astra (yer tell me about it), ended up being stuffed oxygen sensor, revvs bounced from 100rpm to about 1000rpm. And that was after a had to replace a blown engine.

[123R-Prozak]

Sup Anthony.. First i was at tafe today so i asked my teacher about idling funny.. he said is it electric throttle body, i said no its cable.. he then asked what car, i said toyota.. he then went on saying toyota idle slightly higher at cold start to warm it up, then goes to normal reving, if it pulses after warmed up it can be that your stepper motor in the throttle body ( stepper/idler motor that controls this high reving on cold start ups ) is dirty or possibly faulty..

make sense??

laters-Daniel

[Hiro]

if it pulses after warmed up it can be that your stepper motor in the throttle body ( stepper/idler motor that controls this high reving on cold start ups ) is dirty or possibly faulty..

That's the ISCV I was talking about.

[123R-Prozak]

if it pulses after warmed up it can be that your stepper motor in the throttle body ( stepper/idler motor that controls this high reving on cold start ups ) is dirty or possibly faulty..

That's the ISCV I was talking about.

oooohhhhh sorry my bad

tiet, just grap some carby cleaner from super cheap, $13, take the throttle body off and get an old tooth brush and go for it

Edited February 26, 2009 by 123R-Prozak

[the_random_hero]

if it pulses after warmed up it can be that your stepper motor in the throttle body ( stepper/idler motor that controls this high reving on cold start ups ) is dirty or possibly faulty..

That's the ISCV I was talking about.

oooohhhhh sorry my bad

tiet, just grap some carby cleaner from super cheap, $13, take the throttle body off and get an old tooth brush and go for it

Nah, don't need to go to that extent. Just remove the ISCV, give it a good spray with carby cleaner (use the spray pressure to clean, rather than a brush or anything), then either blow it out with compressed air or with your mouth (careful, you can get carby cleaner into your eyes/mouth - both aren't nice. Don't ask me how I know). You can do other valves and whatnot while you're there, I did all mine not so long ago and it made a noticeable difference to my idle.

After, pull the negative off the battery, let it sit for a few minutes then plug back in. This will reset your ECU, which should help also.

[doc_dino]

It's most likely just carbon build up at the throttle body/butterfly valve. Needs to be cleaned with a toothbrush or some other carby cleaner. Should work a treat. You can either do it yourself or just take it to any mechanic so they can clean it for you - very cheap to do.

[jaybee]

I'd be having a look at whatever kind of ISCV you have (usually a valve block on the under/side of the throttle body, controls idle speed depending on certain conditions such as cold engine, air conditioning, power-steering being switched on etc etc). The ISCV screwing up is a common cause on most EFI cars for a hunting or unstable idle.

This guy is spot on. The ISCV is exactly what you should be looking at. If you look at it yourself inspect carefully to see if the valve is stiff. Like hard to move by hand. I had to replce the whole throttle body off a 1zz at work for this. You can't buy the valve seperate and the throttle body assembly is nearly $1500. But thats the ONLY one i've had to replace. A bit of a spray with some carby clean should be sweet. Make sure you spray it down the hole in the throttle body before the butterfly too

~Josh

[tiet]

it was probably the carby cleaner that was the sollution ^_^ problems gone did a full service,

changed sparkies, oil filter and oil, flushed coolant, used carby cleaner, used petrol injector cleaner.

wanted to change fuel filter but didn't know how to reach it, my friend from toyota will be coming by to do it for me lol

thanks for all the help guys!