irratic idle when warm.

[davey red.r]

well after months of work and money ive nearly got the car to where i want it,
one thing that is annoying me:x is when the car gets up to operating temprature, at idle it revs up and down its self,
anyone had these symptoms and what corrected it? im i right in thinking this may be the maf basil fawlty?

davey;-)

 

[billy187]

hiya davey mate, i had this exact same problem a while ago and found it was an air leak...

 

[davey red.r]

cheers food for thought, only does it when warm ill have a check tomorrow,

davey;-)

 

[PobodY]

Maybe the hoses get more stretchy when they're warm... and when they're cold, contract back and make a seal again?

 

[John]

What sort of boost reading you getting on warm idle, should be about the minus -0.5 to -0.6 bar if theres no air leak, if its higher than that then you can bet its an air leak.

 

[GTiR-Shaz]

its most definetly the idle control valve mate, because i hadd the same problem with me ek9, it had been parked up for a while so i put it down to that, soon as i put some milege on it, the problem dissapeared... try taking it for a few blasts and see where you are from there....

 

[projectgtir]

well after doing an expensive diagnostic and manual inspection on my r, nissan said the same as gtir-shaz .they also said it could be the butterflies on the throttle bodies as these coke up and when the car is idling these dont sit completly shut and let air in apparantly. didnt have it done though as they wanted £700 parts and labour and couldnt garantee that it would cure the problem. Think the idle air regulator is £110 and would have had to come from japan,so a long wait.

 

[John]

well after doing an expensive diagnostic and manual inspection on my r, nissan said the same as gtir-shaz .they also said it could be the butterflies on the throttle bodies as these coke up and when the car is idling these dont sit completly shut and let air in apparantly. didnt have it done though as they wanted £700 parts and labour and couldnt garantee that it would cure the problem. Think the idle air regulator is £110 and would have had to come from japan,so a long wait.

That pretty much sums up dealers in one, they are part swappers these days and dont seem to know anything about proper fault detection. If you can take the car to someone who actually knows something about the GTi-R, Nissan are totally incompetant when it comes to R's.

 

[PobodY]

This may sound crazy, but if you've got all that coking, why not use a can of carbie cleaner on them?
Same with the AAC - if you can't get it out to clean it; give it a blast and see if it frees up.
I dropped ~250rpm by doing that... and I'll try again tomorrow (see if I can't get it where it needs to be instead of just randomly squirting down the vacuum hoses).

 

[Shaun]

well after doing an expensive diagnostic and manual inspection on my r, nissan said the same as gtir-shaz .they also said it could be the butterflies on the throttle bodies as these coke up and when the car is idling these dont sit completly shut and let air in apparantly. didnt have it done though as they wanted £700 parts and labour and couldnt garantee that it would cure the problem. Think the idle air regulator is £110 and would have had to come from japan,so a long wait.

I would like to know how Nissan can come to the conclusion that the throttle bodies 'COKE UP'?The only thing that goes through the butterflies is air so where does the coke come from?Only coke i can see is what he's been sniffing from the sounds of things:lol:.Also just to add i've had probably 5-6 sets of throttle bodies over the years and all of them have gaps around the butterflies yet all have worked perfectly with a steady 950 rpm idle.

 

[PobodY]

I think the 'coke' is actually oily residue from having the crank case blow-by going through them. I think that's the main cause of the sticky AAC etc too... I guess the PCV valve doesn't help either. - It's certainly not like what you see on the butterflies of a carburettor (where it's had fuel going over it with the odd back fire)... the worst for it are LPG vehicles. You'd think gas was clean, but it's full of coal tar which coats the metal parts slowly and clogs the nebulisers.

The throttle body cleaner does a good job getting the oily residue out of the intercooler pipes too! The main selling point is quite how cheap it is a fix to try... and how easy it is to apply. If it doesn't work you've lost £4 or so, not £110.

 

[npulsar]

I think the 'coke' is actually oily residue from having the crank case blow-by going through them. I think that's the main cause of the sticky AAC etc too... I guess the PCV valve doesn't help either. - It's certainly not like what you see on the butterflies of a carburettor (where it's had fuel going over it with the odd back fire)... the worst for it are LPG vehicles. You'd think gas was clean, but it's full of coal tar which coats the metal parts slowly and clogs the nebulisers.

The throttle body cleaner does a good job getting the oily residue out of the intercooler pipes too! The main selling point is quite how cheap it is a fix to try... and how easy it is to apply. If it doesn't work you've lost £4 or so, not £110.

iv got the same problem at the min so im going to get
some throttle body cleaner today and give it a go when hot
sits at 1200 to 1500rpm not good for fuel costs:der:

 

[davey red.r]

What sort of boost reading you getting on warm idle, should be about the minus -0.5 to -0.6 bar if theres no air leak, if its higher than that then you can bet its an air leak.

john its reading minus 10/14 alough ive a feeling its an innacurate gauge as its telling me im getting 1.5bar boost and we all know thats not true on a standard ecu no spiking or fuel leaning off,
thanks lads for the input.

davey;-)

 

[davey red.r]

I would like to know how Nissan can come to the conclusion that the throttle bodies 'COKE UP'?The only thing that goes through the butterflies is air so where does the coke come from?Only coke i can see is what he's been sniffing from the sounds of things:lol:.Also just to add i've had probably 5-6 sets of throttle bodies over the years and all of them have gaps around the butterflies yet all have worked perfectly with a steady 950 rpm idle.

my nissan dealer didnt reckon it was coke, they said it was pepsi:doh::doh::lol:

 

[johnsy]

take it to DR PEPPER for a second opinion

 

[ram5ay]

If it's hunting on idle I'd look down the lines of fuelling (vacuum leak, sensor issue - maf, lambda etc) a four gas analyser would be an ideal tool to point you in the right direction, but a trick that can sometimes help is to pull of a vacuum pipe with the engine idling.... if it gets better, could be rich, if it gets worse, could be lean. You can also try spraying brake cleaner around any poss induction join - manifold gasket - boost pipe joins etc, see if the engine changes revs.
;-)

 

[craige101]

Hi mate mine had this problem it was my air flow rgulater got a recoditioned 1 cos my shaft was wobbly in mine now its fine