Ocassional Rough Idle

[bombtrack]

Hi,

I have an issue with my R34 and a rough idle. First a run down of the mods on the car:

1999 R34 GT-t

Apexi Power FC

HKS Dump/Front/Exhaust

HKS Pod filter

HKS turbo timer

Cold air box

Hybrid FMIC

Exedy Clutch

C's short shift

The rough idle appears to happen randomly mainly on start, at any time, cold start or warm start. However it has dropped in to a rough idle in the middle of driving it as well... some time after starting it when idling at the lights. When it does this the car runs very badly and shakes. I don't like to do it, but I can 'drive' the bad idle out by giving it some revs in second, however I cannot seem to rev the problem away in 1st.

The car's just been serviced and the plugs have been replaced. I am hoping I am not losing a coil or worse. I believe it is in need of a tune after some mods, however, it is not a new PowerFC and it has been tuned before(just not with some of the newer mods) AND it had this problem before the new mods(In fact the new mods seem to have improved the issue, perhaps thru better air flow). If it helps, the new mods are the HKS exhaust(turbo back), Hybrid FMIC, cold airbox, Exedy clutch and C's kit(not that the shift kit should cause any problems! )

I have searched fairly extensively on the forum but with no luck as to my specific problem. Any help would be appreciated.

Cheers.

[joeyjoejoejuniorshabadoo]

Anyone, bueller, bueller

[sly086]

Try giving your Aac Valve a clean

http://www.skylinesaustralia.com/forums/in...howtopic=110431

Mine had the same problems with rough idle as you described.

Would sit around 600rpm on idle and had to keep my foot on it.

Gave the Aac and my Afm a good clean out and she runs so smooth now.

hope that helps you

[MANWHORE]

AAC didn't help me. I'm going to give my cold start valve a go

[bombtrack]

Thanks Sly... I think you may have something there. I will give it a go. What I didn't mention in my post is that I also get some clutch/low revs shudder as well which you said was fixed by AAC clean. I thought it was my new Hyper single clutch causing the issue...

Can't wait to see the result.

[bombtrack]

AAC didn't help me. I'm going to give my cold start valve a go

Not sure cold start valve will apply to me as it is happening to me when the car has warmed up as well. If AAC clean doesn't work I will give it a go though... up for anything. Thanks.

[MANWHORE]

Same as mine. My idle is rough always - hot or cold. I was just thinking that since I've already done the AAC and it didn't help, the cold start valve is the next thing for me to clean.

My aac was black inside, but it wasn't jammed or anything. After cleaning it, it was spotless, but it didn't change anything - which means it was working fine to start off with.

[bombtrack]

/bump for great justice (and any more ideas)!