Idle Adjustement Screw

[EsperHamid]

Hey tuners,

1) can the idle adjustment screw be neatly removed from the TB by turning the screw counter clock wise ?!

2) the screw is for idle adjustment depending on which way it turns, however my question what is practically taking place when turning the the screw, does the TB sucks air in or out of the Plenum ?!

I am asking because most silicon has been removed and when I adjust it to the value I want should I glue it back ... wouldn't that block the air flow through the screw ?!

[GhostAccord]

1. yes it can be completely removed for cleaning, I would not remove it during running conditions.

2. The idle adjustment screw is a needle valve. If you turn it counter clockwise you are backing the needle away from the seat and it is allowing more air to be sucked through the throttle body into the plenum.

No need to cover the screw again. There is a rubber o-ring that seals the screw. That silicon was added from the factory to keep owners from making any adjustments to it. The idle speed on these engines is electronically and thermally controlled. It is controlled by the FITV, IACV and ABV.

Note: Only time you should be required to make adjustments with this is if you have made some sort of modification to the engine that would require more air at idle.

If you have made no such modifications and you find that your idle is low. It is probably something wrong with your fast idle thermal valve (FITV), idle air control valve (IACV) or the air boost valve. A lot of times these valves will get dirty over time and and choke off the metered air. These components require cleaning, along with the throttle body in order to maintain proper air metering.

[EsperHamid]

Thanks for the info Mr. ITBs,

One more thing I wasn't clear about, is the air sucked through the screw itself or from inside the TB ?! because inside the TB there's 1 passage for IACV another for FITV and one for the red ugly hose going to Charcoal canister

1 - the TB is in my hands now, OFF Plenum
2 - there's no more silicon for a long time now because I adjusted that screw so many times.

the problem is that when I thought I reached spec idle I glued it so it doesn't move when over a bump or the tire drops in small crater ... but my idle kept dipping as per my previous thread ... when further testing I discovered that the cooling system had air pockets so now after I bled air successfully out of the cooling system, I discovered that my screw adjustment wasn't right and now the screw is glued with ALTECO

2 days PITA, now I am cleaning it, that's why I wanted to know how it really works. All other valves are cleaned and adjust using the DIYs be it IACV or FITV

[GhostAccord]

The air for the idle set screw comes through the throttle body passages not from the backside of the screw. If I remember correctly it is connected to the passage for the IACV, could be the FITV. If you look at the back side of the throttle body you can see the idle set screw tip and the passage going to it.



That's why I always tell people not to adjust the idle set screw until all other options have been covered.... Low coolant, vacuum leak, FITV out of adjustment, valves out of adjustment, dirty throttle body or IACV.

[EsperHamid]

The air for the idle set screw comes through the throttle body passages not from the backside of the screw. If I remember correctly it is connected to the passage for the IACV, could be the FITV. If you look at the back side of the throttle body you can see the idle set screw tip and the passage going to it.



That's why I always tell people not to adjust the idle set screw until all other options have been covered.... Low coolant, vacuum leak, FITV out of adjustment, valves out of adjustment, dirty throttle body or IACV.

actually now that I have 500+ posts, I realized I shouldn't have meddled with it in the first place because I added more options to the list of idle problem causes ... theoretically this screw should exist at all .. but so Honda keeps rolling on the road even with vacuum problem , this screw was added

Thank you for the insight, now that I managed to remove, I understand what you meant gonna clean it along with its shaft ... found glue on the o-ring too ... threads still shining gold/brass after 22 years impressive however the tip is black !!!