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Q For Tuners - Possible To Tune Without Iac Valve?

dori34

By dori34,
in Engines & Forced Induction

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dori34 Grand Master

dori34

Posted
Posted

Hi gang, i just had a custom plenum nade for my 34 neo and ariel left the iac valve off as he advised me to check with my tuner first to see how he would prefer it mounted etc. as its off already and no plates have been welded, i was wondering if its possible to tune and allow the car to run/idle normally with it removed? If not, what will be a side effect of not running one?

i've read that the 34 setups are diff to 33 and most neo boys used 33 iac and tb. if i'm unable to tune it without the iac then whats needed to fit and get the 33 iac working. do the plugs fit or they need to be rewired ? does it matter if its from s1 or s2?

any help much appreciated :D cheers

Rolls Grand Master

Rolls

Posted
Posted

If you remove it how will the car idle? The throttle body is closed so there will be no source of air!

Definitely need an idle air control valve. Whether you can use a different one depends on how they are wired up, I imagine they are just a duty cycled solenoid much like an injector, so as long as the tuning software allows adjustment of the gain factor for the valve you should be able to really use anything.

Feel free to correct me if I am wrong though.

DVS JEZ Grand Master

DVS JEZ

Posted
Posted

it is best to have it or you can put an adjuster screw onto the throttle body to hold the throttle open slightly, this is a bodgy way as there is no adjustment for idle up during air con, lights on etc

put it in an easily accessible place that looks neat/ hidden. you will need to be able to run the hose from it to the intercooler pipe just before the throttle body

dori34 Grand Master

dori34

Posted
  • Author
Posted

hey fellas, cheers for the response.

will be running a nistune so i guess it would be best to have it installed. i'll look into fitting a r33 iac instead and hopefully i can find some information somehwere. i have a/c still and would like to keep it.

STATUS Grand Master

STATUS

Posted
Posted
hey fellas, cheers for the response.

will be running a nistune so i guess it would be best to have it installed. i'll look into fitting a r33 iac instead and hopefully i can find some information somehwere. i have a/c still and would like to keep it.

nistune will freak,

but like guilt-toy said generally it is no issue, map sensor based ecu's dont really care either way, but iac equiped car will always behave nicer especially on the street..

if its nistune use the r34 iac setup remote mounted.

dori34 Grand Master

dori34

Posted
  • Author
Posted

Hey trent, cheers for the info. can you enlighten me more on remotely mounting it.. does this mean i have to block the rear of the valve with a plate and tap a feed to the top of the valve instead? ariel mentioned something about this and said to consult with my tuner but i'm finding it so hard to get in contact with unigroup to get some answers..

PM-R33 Grand Master

PM-R33

Posted
Posted (edited)
it is best to have it or you can put an adjuster screw onto the throttle body to hold the throttle open slightly, this is a bodgy way as there is no adjustment for idle up during air con, lights on etc

put it in an easily accessible place that looks neat/ hidden. you will need to be able to run the hose from it to the intercooler pipe just before the throttle body

RB25 throttle bodies have the adjustment screw allready there.

Just to quickly clarify, AAC (Auxiliary Air Control) is the hose that goes into the intercooler pipe to feed extra air into the engine when the throttle is shut and IAC (Idle Air Control) is the hose from the heater that feeds warm air into the engine when warming up, correct?

Question, how is it that a lot of cars from factory run fine without AAC (Such as a JZA80 Supra). Is it because they are map sensored so it makes it easier? I have tried pissing my AAC off back in the day but the Microtech simply hated it even though it is MAP sensored. So what's the go?

Edited by PM-R33
STATUS Grand Master

STATUS

Posted
Posted
RB25 throttle bodies have the adjustment screw allready there.

Just to quickly clarify, AAC (Auxiliary Air Control) is the hose that goes into the intercooler pipe to feed extra air into the engine when the throttle is shut and IAC (Idle Air Control) is the hose from the heater that feeds warm air into the engine when warming up, correct?

Question, how is it that a lot of cars from factory run fine without AAC (Such as a JZA80 Supra). Is it because they are map sensored so it makes it easier? I have tried pissing my AAC off back in the day but the Microtech simply hated it even though it is MAP sensored. So what's the go?

yeah map sensors dont actually get effected by minor airflow pulses etc so generally dont try compensate... hence rock solid idle.

You can even drill a small hole in the butterfly to help stabilise the idle.

but like previously mentioned its not all that nice for everyday streeters that need pwr steer, a/c etc load compensation.

PM-R33 Grand Master

PM-R33

Posted
Posted (edited)

Only reason I wanted to piss it off back in the day was due to not wanting to run the extra hose when going to the Plazmaman plenum. Now it doesn't really worry me since it is allready set up. It was mainly a "neater" option to not run one at the time :happy:

Edited by PM-R33
STATUS Grand Master

STATUS

Posted
Posted
will just end up getting the plenum modded to fit the IAC, would make life alot easier :D

why is the iac mount missing? is it an old version?

the ones on the website are like the one i had in the shop, had a bolt on position for the stock IAC.

THROTTLE%20BODY%208.jpg

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