bteng

So in the end I had to replace the o2 sensor and the afm all's good now.

Yeah when it starts the wavering idle I can hear a tshhh tshhh sound in time with the revs but cant pinpoint it. I'll give it another go tomorrow.

yeah i thought that as well one of the clamps looks a bit dodgy but i re-tightened it to no effect ima try the soapy water now cheers

well i was just going to swap one from an r34 to test if it fixes the issue some others mentioned testing for vacuum leaks whats the best way to go about this?

OK so thought I had fixed it but after driving for about 20 mins the same thing happened and its back to the rough idling, not sure if tightening that was a coincidence or not now. I guess next test will be swapping the afm. Can i test using one from an R34?

Fixed! Fitted the stock bov, made no difference. Checked the hose clamps on the intercooler piping they were a bit loose so tightened and solved the prob. Cheers for all the advice.

Yes, black smoke coming out of the exhaust when having the idle issue. I have a stock bov i can swapover so I'm going to do that today. Will post results.

OK, so the guy who tunes my brothers car had to drop something off here so he took a quick look at it while it was doing the weird idle and he reckons its the bov. Going to try a stock bov on it tomorrow and see if that fixes the issue.

Basically once it "cuts outs" the whole car jolts and i lose power. This only happens when boosting not when just accelerating lightly. And this is video of the strange idle, it doesn't just sit at low rpms but wavers up and down... was happening this morning.

thanks for the reply, running stock ecu with aftermarket intercooler, bov, pod and boost controller im going to take it back and get him to check the o2 sensor and anything else he think it might be

I have a r33 gts-t s2 which in the last 2 weeks has been having some weird idle problems. I also had problems with the turbo cutting out at around 3500 revs. Took it to the garage but at this point the idle wasn't happening (had stopped doing it the day before despite it doing it for the past 2 weeks every day). They changed the vacuum lines on it and turned down the boost and they checked it with another afm. It seemed fine after this however last night it started doing it again. The turbo seemed to cut out and after this the rough idle started again. When the i stopped at the lights it was idling at between just above 0 - 500 rpm. If I then put my foot down it goes then suddenly the car will go completely quiet like it has died however the revs will stay completely still (at this point it was at about 2500 rpm) then i release the pedal and it fires back up. Any suggestions as to what this could be?