Jump to content
SAU Community

Recommended Posts

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?

Link to comment
https://www.sau.com.au/forums/topic/361549-rough-idle-and-turbo-cutting-out/
Share on other sites

hey mate had similar prob on my s2...went to the tuner and ended up being my o2 sensor as well as a faulty afm....are you running power fc?

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

The turbo wont 'cut out' so to speak. Do you hear the turbo stop spooling or do you just feel a lack of power? Could be many many things. O2 sensor is good for a change, its probably never been changed before. If you rev it past 3500 without boosting(light throttle all the way), does it still limp? Get a compression test done or a leak down test done. Car seems too stock to be suffering like this. Spark plugs, coil packs, O2 sensor, fuel pump etc. There are alot of things to check out. Chuck a consult cable onto it see if it reads anything(although I think the check engine will light up, but don't hold me on that).

The turbo wont 'cut out' so to speak. Do you hear the turbo stop spooling or do you just feel a lack of power? Could be many many things. O2 sensor is good for a change, its probably never been changed before. If you rev it past 3500 without boosting(light throttle all the way), does it still limp? Get a compression test done or a leak down test done. Car seems too stock to be suffering like this. Spark plugs, coil packs, O2 sensor, fuel pump etc. There are alot of things to check out. Chuck a consult cable onto it see if it reads anything(although I think the check engine will light up, but don't hold me on that).

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.

Almost certainly an intake piping air leak. In order of likelihood:

1. BOV

2. BOV

3. hose clamps /joins (but do not over-tighten and break them!)

4. small hose leak

5. plenum leak

6. intercooler leak

7. maybe an AFM problem (wiring or plug since you have changed the AFM).

Edited by simpletool

FWIW

I've had an aftermarket atmo bov on stock ecu and rb25det r33 and it ran fine as stock. Even blocked it for flutter awesomeness didn't cause it to stall or idle rough idle.

Yes, but that doesn't mean this isn't a problem for this engine. Aftermarket BOVs, especially atmo are just asking for trouble. (btw. blocking the atmo BOV means it is no longer an ATMO BOV and will actually CURE stalling and rough idle issues)

Lol at suggesting the 02 sensor. Seems some people have no idea what an 02 sensor does.

Is there any smoke coming out of the car's exhaust on idle?

It really does sound like a faulty AFM.

y u got 2 be such a hero man if you actually read my post i said i had a similar problem i didn't say THE SAME. LOL at urself fooooollll :thumbsup:

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

yeh man best way is to get the pros to check it out...i learnt the hard way wen i took some wrong advice from a internet mechanic $$$$$$$$$wasted$$$$$$$ even tho sum people kno there shit down pat there always a chance of failure ...its worth paying extra for peace of mind..

well let us kno how ya go

y u got 2 be such a hero man if you actually read my post i said i had a similar problem i didn't say THE SAME. LOL at urself fooooollll :thumbsup:

Good one. Why even mention it then? It just confuses him into thinking it could be a cause. It's like me saying "Yeah man, I had a similar problem and had to get my turbo and afm replaced". Suddenly he will freak out into thinking he needs a new turbo. Comprende ese?

yeh man best way is to get the pros to check it out...i learnt the hard way wen i took some wrong advice from a internet mechanic $$$$$$$$$wasted$$$$$$$ even tho sum people kno there shit down pat there always a chance of failure ...its worth paying extra for peace of mind..

well let us kno how ya go

"The pro's". Spoken like some one that has no clue about cars. This type of attitude on here will not get you far.

Hence why I asked about the smoke out of the exhaust. If you have an intake leak as bad as what your car appears to have it will be overfueling a lot and you will usually have black smoke coming out of the exhaust. That BOV would have to be leaking hardcore to cause an idle to be that bad ie. be literally completely open.

Good one. Why even mention it then? It just confuses him into thinking it could be a cause. It's like me saying "Yeah man, I had a similar problem and had to get my turbo and afm replaced". Suddenly he will freak out into thinking he needs a new turbo. Comprende ese?

"The pro's". Spoken like some one that has no clue about cars. This type of attitude on here will not get you far.

obviously you dont know much better than me if your post sounds just like mine...wen u mention AFM problem??!....you need to relax !! if you kno more than a professional import mechanic i apologise.. if you dont maybe you should get off ur hi- horse and chill. Dude y would he freak out geezzzz ... I just wanted to suggest he get his tuner to check it out first rather than him spending $ on uneeded shit...and then then you start having a cry ...

you say "This type of attitude on here will not get you far" ....ahahhaahahhahahahahhahaaha thats priceless dunno wat in helll u mean by this but maybe your just having a BAD DAY..i think you have the attitude issue mate i love my skyline and respect all nissan fans ... thats my attitude!!!!

:w00t: BOOOOOMMMM!!! ......n yehh its like that!!! maybe this will cheer you up a bit :banana: aahaha :thanks:

Sounds like it could be fuel pump to me, often they will cut in and out when they are dying hence fuel starvation where you won't stall but you'll get a massive lean condition and it won't rev.

It could however be one of many many things, I would recommend taking it to a workshop and letting them sort it, without the proper equipment it could be quite hard to diagnose. If you don't want to though I'd get a consult and check for error codes to rule out sensors, then chuck it on a dyno to see if its leaning out due to a fueling issue.

upon my first read I would have assumed AFM or fuel pump. The idle issue does sound more like a leak in a vacuum line or intake (BOV) though. Most likely not an O2 sensor though, as they only lean out fuel mixtures when cruising.....

I was having some dodgy shit going on with my car cutting in and out at rpm and load, and it was the AFM, it wasn't hunting around on idle like that though, thus why a vacuum leak would make sense .

Edited by JKR-32

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
    • 310mm rotors will be avilable from Australia, Japan, and probably a few other places. Nothing for the front can be put on the back.
    • The filter only filters down to a specific size. Add to that, the filter is AFTER the pump. So it means everything starts breaking your pump even if its being filtered out.
    • Just like in being 14mm too small (296mm) makes it not fit, being 14mm too big (324mm) it also won't fit. You want to find the correct rotor.
    • @GTSBoy Ok so that was the shops problem...they showed R33 rotors on R34 page and i did not know 296 do not fit(and are for R33) Yes i bought "kit" with rotors and pads. Pads are ok(i have GTT calipers front and rear). They have some 324mm but no 310mm. So i dont know if they would fit. I have 17inch LMGT4s So another question. Can i fit those in the rear or they are just "too" big for that?
×
×
  • Create New...