[mitch32]

Hello,

I installed an oil cooler and had to remove my plenum. I replaced all the gaskets, and also cleaned the throttle bodies as there was a fair bit of carbon buildup. At the fully closed position it was hard to see if the throttle bodies were opened but looking at them with a light I could see they were opened (not much but a bit). Now I have everything back together and my idle is now at 1700rpm (before idle was 950rpm). I tried to adjust the AAC but it did nothing even with the screw bottomed out its at 1700rpm. I'm guessing the throttle bodies have to be adjusted but I am unsure.

If I should adjust the throttle bodies what is the best way.

 

[T04Z GTR]

Never ever clean them out..!! there is a special sealant in there to get them to seal properly when there in the closed position...

It cant be bought & unfortuantly I think your going to have to purchase your self another set of T/B's which havent been cleaned to rectify the problem...

 

[NISFAN]

Yeah, that 'carbon' you cleaned out? That was put there during manufacture to seal the butterflies when closed.

I'm not sure if anyone has tried silicon sealant to re-seal the butterflies. Obviously applied to the back side of each half.

 

[Thrust]

As above. Quite a few people have a high idle problem possibly caused by this. There are threads about it on the site somewhere.

 

[mitch32]

I used throttle body cleaner. It was black on the back of the throttle bodies but it was loose dirt/carbon, I could rub it off by lightly pressing my finger on the butterflies.

 

[lightspeed]

Download the R32 workshop manual and follow the procedure in it to the letter.

Do not ever adjust the stop screw that sits on the "bridge" bracket on the plenum - this is factory set and never needs adjusting.

The factory sealant is nothing to worry about if the throttles are all set as per the procedure.

 

[NISFAN]

I don't think a throttle position reset will cure the problem.

The fit between casting and butterfly is not great, and with ITB's it doesn't take much of a leak on each to make a big difference to the idle speed.

Hence the Nissan goop.

 

[ANDY H]

i cleaned and matched my throttles! and set the idle to 950rpm all was good!

 

[infamous_t]

i cleaned and matched my throttles! and set the idle to 950rpm all was good!

Did you get your hands on oversize butterflies?

EDIT: Nevermind, I mis-read, I thought you said you 'machined' the throttles

 

[mitch32]

I've read of putting some hobby enamel paint on the throttle bodies to seal them. I'm gonna do some tests this weekend and see how it goes. I can adjust them so that they fully close but like NISFAN said there may be a small gap between the casting and the butterfly even if it .001" its still may affect idle I rather seal them completely. That Nissan goop is there for a reason too bad the manual doesn't explain what it is and doesn't have any warning not to clean them. Too bad also that the plenum takes a good 2-4 hours to get off and put back on just to put some cheap enamel paint on.

 

[gunner]

Ignore everything they all said,nissan don`t fit any goop or anything,you can adjust all throttle bodies(and i have done for the past ten years,yes on skylines).At the bottom of the three pairs of throttle bodies are grub screws with an 8mm nut(requiring an 8mm socket not 8mm thread)loosen the nut and adjust the screw till you feel resistance in the throtttle bodie by pulling it open/closed(you will have to disconnect each linkage from the throttle assembly),by adjusting the grub screw your letting the butterfly close therefore closing the air gap,be careful to hold the grub screw in position while tightening the lock nut,it has a small amount of loctite on it (usually red),it is difficult and only do this if you are mechanically competent and understand what i`ve wrote.