Idle Engine Hunting

[shubby0901]

Hi guys,

Ive recently bought a R33 and am having an issue with it. While in neutral, just standing still, the cars throttle hunts (if that makes sense). The revs rise and fall, sometimes a really small amount, sometimes rises to 1500 and then drops to pretty much 0 where it feels like the engines gonna turn off.

Car is a manual, completely stock as far as I know.

The mechanic said lots of R33's have this problem so thought id have a go to see what peoples opinions are.

[Ben C34]

Clean out the iac. Search for a guide or whatever. Or ask your mechanic why he didn't just tell you the reason.

[shubby0901]

Clean out the iac. Search for a guide or whatever. Or ask your mechanic why he didn't just tell you the reason.

Will try to have a look.

The mechanic told me about it when I got it inspected, he said they will try to clean the throttle body and then see if they need to replace parts.

People on here usually seem to know exactly whats wrong so I thought id ask.

[Ben C34]

Don't clean the throttle body. That's not the problem.

Hopefully that's just lost in translation and your mechanic actually knosw what he is doing.

Edited October 20, 2014 by Ben C34

[shubby0901]

Don't clean the throttle body. That's not the problem.

Hopefully that's just lost in translation and your mechanic actually knosw what he is doing.

Didnt think it would be hence asking people who really know

[Ben C34]

So I've told you.

Iac.

I'm sure there's probably a guide or something somewhere.

[dyl33]

This is what benC34 is referring to I think http://www.sau.com.au/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/ easy diy job

[shubby0901]

This is what benC34 is referring to I think http://www.sau.com.au/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/ easy diy job

Thanks .

I have bookmarked this page already, just waiting for a day when I have a bit of time to do it, tried to drive today with the Air-con on and the car stalled everytime I stopped cause the revs dropped...need to do this asap.

[SkudR33]

Thanks .

I have bookmarked this page already, just waiting for a day when I have a bit of time to do it, tried to drive today with the Air-con on and the car stalled everytime I stopped cause the revs dropped...need to do this asap.

Definitely the iac! Scrap the mechanic and attempt to clean it yourself, a quick way to test this theory - spray some carby cleaner into one of the hoses attached to the iac and see if it temporarily fixes your issue.

[shubby0901]

Definitely the iac! Scrap the mechanic and attempt to clean it yourself, a quick way to test this theory - spray some carby cleaner into one of the hoses attached to the iac and see if it temporarily fixes your issue.

Dont have a carby car so dont have carby cleaner....off to supercheap tomorrow.

Unless CRC degreaser works? Dont wanna try without knowing what it does..

[Dylan454]

It's really not hard 4 bolts, a hose and a plug then clean it and put it together, mine would always stall when I had the lights on but cleaning the valve fixed it

[SkudR33]

I personally wouldn't recommend degreaser as it leaves an oily residue behind which needs to be washed off...

[shubby0901]

It's really not hard 4 bolts, a hose and a plug then clean it and put it together, mine would always stall when I had the lights on but cleaning the valve fixed it

Yeah doesnt seem hard, just need time when I dont have uni,

I personally wouldn't recommend degreaser as it leaves an oily residue behind which needs to be washed off...

Yeah I thought so. Will wait for the proper stuff, till then just keep the revs up at the lights.

[Dylan454]

It's pretty embarrassing when your car just wants to die. Especially atva car meet

[shubby0901]

It's pretty embarrassing when your car just wants to die. Especially atva car meet

Happened to me while braking, I had the aircon and the radio on...didnt realise what happened till I noticed the HICAS light was on and realised the car had actually turned off...

[shubby0901]

Just quickly, is it possible to turn the screw so the car idles at like 1200 temporarily so that it doesn't stall? Until I get a chance to get the whole system fixed...or is that not good for the car?

[Ben C34]

Try it. It won't kill the car.

[shubby0901]

Try it. It won't kill the car.

So I tried to turn the screw, there was no significant changes to the RPM, went from 900-1000, even though I unplugged one of the 2 plugs on the throttle body, but I drove with the Aircon and radio on and it didnt stop...so I guess it did make a difference...

[shubby0901]

Did the cleaning today. Will report back on its effect. Immediate observations report a very smooth car, smooth revs and smooth idle. Idle set to 950 rpm

[Krishy]

This is exactly the problem that I was having with my 33. This issue points to the AAC valve. This is the valve that allows air into the motor when the throttle is closed, hence keeping the motor running. This normally has a carbon buildup and clogs the airways. That DIY link that was posted up is exactly what I used to take the aac off and give it a good cleaning. Problem solved.