Jump to content
SAU Community

Aac Valve Is Missing From My Car

Proximity Motorsport
 Share

Recommended Posts

Proximity Motorsport Experienced

Proximity Motorsport

Posted
Posted

Hey,

I just purchased a R32 with RB25 in it. It has a Microtech ecu. Now the standard plenum was removed from car when i bought it, and a greddy copy was dummy fitted. After inspection, the standard plenum has a plate over where the AAC valve went, and its been sealed, and the new plenum, which owner said was purchased second hand, has had the hole welded up, and im confused as i dont know how the car will idle? I dont know a single thing about microtechs..but to me i would think you will need air somehow to make it idle.. Any Ideas? Anyone know of removing aac valve how to keep car running??? Problem is i havent started car yet cause its all in bits, and ive never heard it running

Link to comment
https://www.sau.com.au/forums/topic/250031-aac-valve-is-missing-from-my-car/
Share on other sites
Proximity Motorsport Experienced

Proximity Motorsport

Posted
  • Author
Posted

you mean so the throttle only closes 98% or something.... i heard this can be bad when you back off, the revs dont drop quick enough?? true or false anyone?

08yannch Rising Star

08yannch

Posted
Posted

it is just the throttled body has been adjusted so that it is always open. this does not mean that it is all of the way open is may only just a little. i dont think it will damage any thing when u back off as long as ur not idling to high. but dont take my word for it.

the way that i see it is if nothing bad has happened and there ar no funny sounds then it should be fine

BrynDETT Community Regular

BrynDETT

Posted
Posted

no you dont need aac... atleast that has been the case with a 4agze ive been working on... its running a haltech map based ecu.. so obviously the haltech didnt support aac so we blocked up the idle control holes in the throttle body and just set the idle with the idle screw... works like a charm..

nizmonut Community Regular

nizmonut

Posted
Posted

The Auxaliry air control valve is there for the purpose of adjusting the idle under load of air conditioning or alternator load, it adjusts idle up to 500 rpm, the ecu also uses it to determine engine revs at idle whilst warming up, however it is not critical to the performance of the engine as it becomes redundant once rpm reaches 1500.

MBS206 Grand Master

MBS206

Posted
Posted

If your aftermarket ECU is running the AAC valve, leave it on.

To get a car to idle up without one, means you have to fudge things with timing.

To force a car to idle up, say if RPM drops to 600RPM, you throw ALOT of timing in, and it'll bump it up. If it's idling high, you reduce timing so it drops down. It's all in tuning the timing map, and fuel map to make it idle correctly.

Things you will lose though, are like the idle up when you turn the steering wheel, or turn the AC on or lights on.

Some ecus allow you to add or reduce ignition timing VS temperature, this is how they can idle up, when cold. But nothing else can be idled up.

You can do this whether the ECU runs an AFM, or a MAP sensor. You just need to know how to make it do it.

Last I heard, the Microtech can't control very many AAC valves. But if your ECU can, LEAVE IT ON THERE! It'll make life alot more simpler then "removing a few hoses"

Proximity Motorsport Experienced

Proximity Motorsport

Posted
  • Author
Posted

thanks alot for the help guys, that sorts me out, My car never had one when i got it so i wont bother trying to hook one up, when i get it running i just hope she runs alrite, thats alot... if i have trouble with the A/C or the P/S stalling me ill just bump the revs on idle to 1000rpm or something.

Thanks alot for the help, Happy new years

ps...just for the record my old r32 had map sensors power fc djetro and it needed the aac valve, but when it was fully open was still not getting enough air so i left it on, but i also opened the throttle a little.

cheers

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • AdiR34
      R-chassis INNER tie rod torque spec?

      By AdiR34 · Posted

      I'm seeing torque specs all over the place for the OUTER tie rod, but none for the INNER tie rod, where it connects to the steering rack. Even in videos, people are just tightening em up as much as they can with a wrench and that's it. Anything tightened down without torque makes me nervous. Anyone know what the spec is for it?
    • Curlyfred
      Hiya!

      By Curlyfred · Posted

      Hope you had a great time here in our tiny country.   The JDM scene we have here is quite small, it's mostly BMW, Volkswagen with burble tunes haha. But the few JDM cars we do have in the scene are pretty nice. Some of my friends drive cool s14's too. Both built engines, red one makes abt 500, blue one abt 400 i think?
    • Nizzy_R34
      r34's love to squeal

      By Nizzy_R34 · Posted

      Ye good idea , would have never thought of something like that. Might aswell do it to every pulley and the balancer while I’m there 
    • GTSBoy
      r34's love to squeal

      By GTSBoy · Posted

      Use an LS1 or similar, via kit like Frenchy's. But.... It's probably not the alternator. It sounds like belt squeal, which would be because the pulleys are glazed. Rub every groove on the pulleys with 120 grit paper. Report back. Oh, and new belts afterwards too. The old new ones will be shitted up already.
    • Nizzy_R34
      r34's love to squeal

      By Nizzy_R34 · Posted

      Hello all I have 2 r34 sedans , one turbo one na, only recently aquired the na 34.  Man what is with these things.... My turbo 34 started sounding like a super charger, it was screaming at anything above 4000rpm , I took the alternator apart and replaced the front bearing which is the only one I think you can access and it did not fix the issue so presumably the bearing in the rear of the alternator is gone. ( diagnosed it was the alternator by taking off the aux belts one by one to figure out which pulley or bearing it was )  My friend gave me one he had lying around, Installed it , it did not squeal for maybe 500kms and now its started to squeal again briefly on startup  Recently got an na r34 and I replaced the timing belt, water pump + all the auxillirary belts. Runs amazing but it suddenly developed the same squeaking problem but significantly worse, Ive had my neighbour come down screaming at me because it was waking her up everytime I moved the car. It takes a good 2 minutes before it quietens down.  Im yet to diagnose where its coming from but im fairly sure its coming from the alternator aswell. My question isnt about how to fix it but rather where can you get a new alternator for an rb25 neo??? Ive searched everywhere but I havent been able to find a direct fit oem type replacement thats not genuine. All the automotive stores sell an oex one - BXA035 - which I picked up for cheap through a friend with staff discount , got it home only to find the connector is completelty different.... As far as im aware bxa035 is for rb20/30's and after a bit of figuring out the bxa035 has an ev14 type connector, which is tiny compared to the rb25 connector. I actually had an ev14 connector lying around which I was considering just replacing the bigger plug with to get the alternator working but the bxa035 is rated for 70amp vs the rb25 alternators are 90amp ( or so ive been told ? ) That paired along with the fact im about to install an amp + sub in the back and I have the stock sized small battery Im not sure itll do the job unless anyone has another opinion?  I know and have seen all the websites selling the ls1 alternator conversion kit but I am not going down that route, nor do I have the money to. Hopefully I can figure out how to get 2 brand new alternators for both cars. I would buy second hand which there seems to be many of but considering how common this seems to be im sure If I installed a second hand one it would start squealing in no time  Or even better if anyone knows how to fix the issue directly with the alternator itself... Any input appreciated Thank you     Link for bxa035 connector picture
×
×
  • Create New...