Rough Idle

[AdamsR33]

Okay people, i have stock r33 GTS-t S2, went to track day down at wakie and all went well. come home car was all good, a few days later the car started to idle rough, idling down to 500-400rpm, kept running though and hasn't stalled. When i pressed the accelorator car was fine, didn't miss had good power still. I changed the plugs which looked like shit and thought maybe that was the problem but no, idle still rough. I have noticed that when i change gear sometimes or back off sometimes i get popping in the exhaust. Never run the car below just under quarter of a tank of fuel and always premium at worst. Actually since trackday only run BP ultimate. Car isn't running hot or anything just rough idle. I did turn the idle up a smidge and seemed to fix it but it has come back. i don't think turning the idle up is my answer.

It doesn't seem to be running lean as fuel usage is about right.

Only mods i have are, dump pipe and 3inch exhuast and pod filter, i do have a dual stage boost controller installed but its set on stock 8psi when i'm on the street, when i'm at the track i'll turn it up to 10psi but at wakie it played up and overboosted so left it on 8psi.

Any suggestions??

Maybe fuel filter, pump maybe, even a leak?? Don't know, thats why i'm asking you.

Cheers Adam.

[Mickroy]

Could be a bazillion things... might pay to start by doing ecu diagnostics. Should be something about it in the diy/faq section.

[GTshortie]

Have you tried cleaning your AFM with CRC contact cleaner? that might be worth a shot.

my 2c

[Craved]

take the AAC off and clean as well Adam ..

other option is the TPS might need a little adjustment

[AdamsR33]

take the AAC off and clean as well Adam ..

other option is the TPS might need a little adjustment

WTF???

Okay sorry should of mentioned i have cleaned the AFM friday before trackday, so two weeks ago today. Chris what is AAC and TPS, and how do i clean them.

Okay Chris don't answer that i'll do a search mate, might pick your brain later though if this don't work, maybe even have a look at it for me??? be much appreciated.

[Craved]

haha ok .. TPS is easy with a 6mm socket .. its the throttle position sensor, on the throttle body -- may be a bandaid fix though

AAC - auxilery Air control (idle control).. big DIY on how to clean them on here..

[AdamsR33]

haha ok .. TPS is easy with a 6mm socket .. its the throttle position sensor, on the throttle body -- may be a bandaid fix though

AAC - auxilery Air control (idle control).. big DIY on how to clean them on here..

Thanks Chris, i'll be doing this tomorrow.

http://www.skylinesaustralia.com/forums/in...mp;hl=ACC+clean

[Craved]

haha OK adam ...

[AdamsR33]

Okay cleaned my ACC but noticed i had a leak in a small hose just above the ACC valve after i cleaned and replaced it, don't know if i broke it while i was fiddling with the ACC or not, but fixed it. As for the main problem being fixed i don't know, on the sticker under the bonnet it says to set the idle at 650rpm, so i did and it seems to hold idle now but occasionally it 'misses' i don't think it is missing but i don't know how else to describe it. Might be time to get a tune from a shop.

Anyway thanks for those who responded, i did actually learn somethings about my car. I will post when/if i find out what/is my problem.

Cheers, Adam.

[Craved]

that would be the factory boost guage feed pipe above the AAC, a slight pop in the exhaust seems to be fairly common on most rb's though..

[AdamsR33]

Chris thanks mate, i owe you

Okay it seems to be all good now, nice and steady idle. If it was the hose that was broken before or if the ACC valve needed cleaning i don't exactly know which was the problem but both have been done and now she idles like a kitten.