Mestre

Anyone able to point out where i can find this at? My idle is rather high and i have no idea why. I want to adjust that and maybe by doing that my idle will drop off a little bit :/

T.c.

technonovice

The screw is recessed within the throttle body. When you remove the intake elbow, you will see a finger sized hole at the bottom on the firewall side of the throttle body. The thing is, though you maybe able to close the screw enough to lower the idle, you likrly have avacuum leak somewhere. When I bought mine the car idled well. Then it began to idle higher....then higher. I found the screw was already fully closed. So my quest began. It ended with the LIM gasket. The gasket was blown at both secondary ports.

riptor

what about low idle. my car was idleing good when i bought it...now 15k later, it idels at like 550-650. when warm. vaccum leak as well..?

adam c

iTrader: (2)

Mestre,

How high is your idle? If it is just a little bit high, use the idle adjustment screw under the drivers side of the throttle body. You will need to use a small mirror to see it the first time you adjust it. Do not remove the elbow.

If your idle is very high, use the adjustment screw on the front of the throttle body.


Riptor,

Your car is fine. Just idle it up a little bit if you don't like it where it is. It won't hurt anything if it is a hair low.

HotWheel

Thats the air fuel mixture screw !

The Idle screw is on the throttle boddy towards the front it has a little locking nut on it with a straight screw tip you loosen the lock nut and turn the screw right for higher rpms and turn left to lower rpms !don't forget to tighten the lock nut when your done !

adam c

iTrader: (2)

Officially, it is the air adjustment screw. It is what you use to make minor adjustments in idle speed.

jd to rescue

iTrader: (3)

In attempting to head off a flame war, idle adjustment is a mixture of the air bleed screw (bottom of throttle body) and the idle adjustment screw (the screw at the front of the throttle body in a vertical position with a locking nut at the base). It is my preference to make adjustments by first adjusting the idle screw at the front of the throttle body and then adjusting via the air bleed screw when the idle screw does not compensate. Kento explained this a few months back, but you cannot find the thread because the SEARCH function is currently f*%#@d.

adam c

iTrader: (2)

There is no flame war here

From the 94 Mazda Factory workshop manual. Page F-17 under idle speed:

5. If not within specification, adjust the idle by turning the air adjustment screw.
6. If not within specification when air adjustment screw fully closed, loosen the locknut and turn the throttle adjusting screw to set the idle.

You don't need a flame suit when you are right

PhoenixDownVII

I'm having an odd idle'ing problem too.

I didn't change anything on my car to cause this. The car sat for a week because of the ugly
rainy weather (and the lack of sun for 6 days straight) we had in the NE
last week.

Started the car and it had it's normal condensation "smoke" for 30
seconds, and when I drove it, it boosted fine, the vacuum was fine,
everything.

After being warmed up, however, coming out of gear into neutral, the
RPM's dropped too low, sometimes stalling (Like when I am maneuvering in
a parking lot).

This happend to my MR2-Turbo after an aftermarket BOV was put on due to
its MAF system (Rx7 is MAF).

I know the TPS can usually help hold and adjust a stronger idle, but
shouldn't this "problem" be a gradual thing? Or can my car's idle just
get thrown off out of nowhere?

I almost feel like something alongside the intake of air side (or
letting it out, like the BOV) is clogged or malfunctioning. I also have a check engine light (Code is for the EGR Valve), and given the EGR is being screwy, could it be stuck open and recirculating exhaust gas full-time, after warmup, and is causing a lower idle because of a drop in pressure (or increase in certain extents rather)?

I suppose a TPS adjustment is in order?

Just is odd it decides to idle low out of nowhere...

*Posting this here b/c I can't make a new post because the forum's being wack*

quicksilver_rx7

The RX-7 uses a speed density MAP system. NOT a MAF system. As for the low idle, that could actually be several different things. ISC (idle speed control) valve can go bad and cause a low idle, and of course the ultimate problem - LOW COMPRESSION

jd to rescue

iTrader: (3)

I'm happy for you. Like I said, it is a mixture of the two. My preference is still to adjust at the front of the throttle body first. In 12 years of 3rd Gen ownership, I have never had a lasting idle problem. I have yet to adjust the "air adjustment screw", except for one occassion.

adam c

iTrader: (2)

Then its nice that you have learned something today

technonovice

Have you checked to see if your idle speed control is connected and working?

technonovice

Have you checked your dashpot?

Mestre

A. what's a dashpot?

B. where's the isc?

Guy had a haltech before.. I have no idea what he's cut and im finding out about all sorts of things randomly when im LEASE wanting to.

T.c.

technonovice

You need to download a copy of the factory service manual.

riptor

is that in the downloadable manual as well..?

HotWheel

Just an F.Y.I

We all learn something everyday !

I purchased the alt / waterpump pulley kit from Pettit . removed the air pump
that was waying the car down and was not connected except to keep the belt spinning.


Anyway when I removed it the Idle seemed lumpy so I did play with both screws.

And I was told By Jeff to ajust the air fuel mixture screw under the intake elbow.
1/4 to a 1/2 turn out It worked !

each 7 is different in MODS and altitude !

Mine is running like a rocket ! had trouble with intercooler pipes and clamps

technonovice

For myself, I'd never fiddle with the air fuel mixture screw without having a wide band sensor. I do have one, but you want to be careful with that.

PhoenixDownVII

I'm going to address this issue with the manual, after looking over any leaks.

As I explained, my situation is odd only because it happend "overnight". Not after a day at the track, some high rev' high MPH pull. It literally just decided to have a lower idle once it was warmed up than usual.

However, my car is equipped with a Knock Sensor that I believe had an altitude setting that perhaps is not calibrated correctly with the car's new location (Car came from Boston, and is now in Orange County NY). This is also one of the hottest days the car has been driven in with me. I bought the car in August and it didn't see many moist/hot days driving from Sept-May in the Northeast.

I also am not an advocate of a "temporary" fix. Raising my idle may make up for something else causing it to be lower, or it can simply be that I just have to adjust it, Period.

I hardly can consider it a compression issue, my car is and has acted as it was since day 1 with me, which was at great compression.

I made a typo with the MAF vs. MAP issue, I was trying to point out that I understood my Mr2-Turbo would act differently with certain air intake/exhaust upsets because of its "Different" system.

technonovice

My idle problem manifested itself in non track driving(during the winter) as well. You are wise to not mask the problem and to pursue the real cause. It could be that a popped or torn hose or even a LIM gasket. The original gaskets don't hold up so well.

Kento

The air bleed/air fuel mixture (whatever you want to call it) screw only affects idle and very small throttle openings.

Many call it the air bleed screw because that's exactly what it does: it "bleeds" air past the closed throttle plates to assist with idle. It has no affect whatsoever on the fuel delivery.

The reason for the air bleed screw is due to the fact that the intake pulses make it extremely difficult for the throttle plates to properly control the idle airflow when they are almost fully closed. This is why the machining/matching of the throttle plates to the throttle body clearance is critical and requires precision during manufacture. The air bleed screw helps alleviate those airflow control problems, and allows for a smoother idle.

Because it is an actual air bleed that isn't controlled by the throttle, you want to try to set your idle with the screw as close to fully closed as possible. Once you get to the point where the idle adjustment screw has problems making any difference, you use the air bleed screw to achieve the proper idle.

HotWheel

I'll keep this inmind thanks for your input !

jd to rescue

iTrader: (3)

There's the explanation we've all been waiting for. Now we all know something.

Thanks Kento.

Mestre

Thanks Kento.

T.c.