Jump to content
SAU Community

Recommended Posts

Hey SAU,

Couple of days ago i picked up my r33 gtst with a second hand motor as i blew the previous motor again.

Car is running perfectly except it idle hunts on clutch in.

What will happen is cold start is fine, then once the temp hits normal, drive then clutch in and the revs will go to 2k for a brief moment, then drop to 1.5k where it hunts between 1k and 1.5k, after a random amount of seconds, the idle will then smoothly move down to 850rpm and stay there. Once it hits 850 rpm it will stay there till next take off/clutch in etc. Note it never goes below 850rpm.

I have searched and found the aac issue so that's been cleaned but didn't make a difference unfortunately. The car did sit for around a year until i got the engine swap done but was started a few times to prevent things clogging up like injectors etc.

I did find some stuff about apexi PFC idle learning but i don' have datalogit so can't perform the procedure without losing my tune.

Would the pfc need to perform the idle learning procedure as the engine has been swapped, even though all mods are the same ?

Car idled perfectly for the last two engines and i know the previous engine swap had the ecu retuned as it got moved to e85 then.

Mods are

apexi pfc

garrett gtrs

intake, fmic, z32, coilpacks, copper plugs, tbe,

740cc injectors

That's about it that would affect idle.

Thanks

Link to comment
https://www.sau.com.au/forums/topic/416285-another-r33-idle-hunting-thread/
Share on other sites

Man I have exact same issue...got me stumped for a while...it had issues with startup that were played with on the weekend and it made a big difference to the cold start especially ,that I would say it's no longer an issue.. But soon as I drive it and pull up at traffic lights ,bang 2000rpm...drops and bounces between 1-1.5 then after 30seconds or so of this it drops to normal.idle...problem is sometimes it will take minutes before it settles and you get funny looks from cars beside you as the revs bounce around....I'm just waiting for a cop to pull up and ask wtf is going on with my car...

it probably does this 90% of the time and it seems to be more pronounced on e85...on pulp it is rarely an issue but still happens..As you say it only happens after a drive too..if I start the car on the spot the idle is usually fine..drive 20mtres clutch in and there it is again...

For a while I noticed that if I would start the car let it warm then disconnect the aac top plug it would be fine. (Though this is not something you want to do everytime you drive). But after a while this bandaid solution fell off anyway and it was hunting yet again..

I am running an Adaptronic with inbuilt MAP fwiw

Suggestions have been made around latency issues or a return to idle issue, but I'm still not convinced its just not something mechanical..

Hey guys,

Thanks for reading and answering my thread, much appreciated :)

I returned to my original mechanic today as he asked me to swing around so he could have a look at it and it was fixed in 5 minutes huzzah!

Artz,

What you described is bang on with what was happening with my car. Anyways, last night i cleaned the aac valve as per this thread: http://www.skylinesaustralia.com/forums/topic/110431-diy-aac-valve-cleaning-idle-reset/page__st__100

Took the car to a workshop today and after 5 minutes playing with the idle screw on the aac valve/housing, the idle no longer hunts! We basically just let the car warm up, then turned the screw to one extreme and work back and forth from there, testing now and then with poking throttle then back off, touch the brakes and clutch in. Maybe worthwhile cleaning the aac too if you by chance haven't done it ?

Hope this helps and your problem turns out as simple as mine.

Mate ill put my 2c worth in here, I had the exact problem as well but I was running stock turbo. Had pfc tuned and started hunting allllll the time cold hot whatever so I played with the AAC valve and it sorted it but only for a little while then it all started again.

Anyway, got a gtrs and 740cc injectors exactly as u have lol and had it retuned, any now I have absolute perfect idle 100% of the time.

So I'm guessing u may have an issue with ur tune (maybe not) but that's just my experience anyway.

Good luck

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

    • Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...