Similar Idle adjusment procedure??

[358stroker]

On our 94-95 stangs is the idle adjustment procedure the same as the 93 and prior stangs? This is my understanding:

1. Disconnect the battery's negative terminal to reset/clear the computer's memory. Leave it disconnected for 30 minutes. WARNING: Whenever removing your battery cables ALWAYS disconnect the negative battery cable first and reconnect it last. Otherwise you could destroy your computer or cause a battery explosion.
2. Disconnect the plug going to your idle motor which is located on the front of your throttle body.
3. Reconnect your battery's negative terminal.
4. Start the engine, and set the idle to the rpm you want with the stop screw on the bottom of the throttle body.
5. Turn off the engine.
6. Reconnect the plug on the idle motor
7. Make sure all accesories (radio, blower motor, a/c, lights, etc) are off and start the engine.
8. Let engine run for two minutes.
9. Turn engine off and wait two minutes then restart engine and let idle for two minutes with all accesories on.

 

[urban96]

also wondering if this works because i need to raise my idle a bit

 

[mo_dingo]

That procedure will work fine for our cars too.

But there is a screw in the top of the throttle body, (alan head screw), and that will cause hanging idle if set improperly.

You need to tighten that top screw till it stops, then back it off 1 1/2 turns. Do this at the same time you are adjusting the throttle stop screw.

I would also completely remove the throttle stop screw and replace it with a hex head screw that is the same length/thread type. Since it doesn't have a head on it, it's a PITA to adjust. That way it will make it exremely easy to adjust your idle in the future, if necessary.
Scott

 

[rgs]

anyone got any pics on this procedure?

 

[R.J.]

Try setting your idle with the procedure below. It is a mechanical and electrical adjustment so the computer is forced to learn the new setting instead of just slowly setting it back! It worked for me and my buddy after his TFS H/C/I

MECHANICAL IDLE SETTING

'94-'95

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.

 

[RIO5.0]

R.J....That nails it right down.....definately should be a sticky... Think I'll stash that one for future reference...

 

[R.J.]

When I found out how good this works I stashed a printed copy away and I have it saved on my computer. How would it get made into a sticky?

 

[358stroker]

RJ..
Being that I performed the fox body throttle body swap on my 94GT, would my first post be the correct way?? Or is your post correct? They seem very similar.

 

[RIO5.0]

I used this link when I swapped over to my Fox set-up...I set my idle to 750 and then did steps 3-5....It worked the balls and nailed it first time...On the Fox you have to set the TPS also as it is adjustable..
RJ's write is along the same line...but more SN95 TB specific??, as the Fox doesn't have the same idle screws, meaning the one under the White plastic cap...Most important is to do it cold...
http://www.muscularmustangs.com/maintain.php

 

[HISSIN50]

Andy is right. With foxes, if the IAC is clean, their cold idle is alright. So one sets the hot idle (with no IAC assistance) and knows that the cold idle will be kicked up a bit from there.

As an aside, some of the fox TPS's are not adjustable stock, so dont freak if you have to hog-out one of the holes out a bit to make it so.
Fox puters zero out the TPS reading upon throttle closings, like SN puters do. But often this is not so hot with foxes, so they are adjusted anyhow, to deal with idle surge.

If the fox set-up uses a fox IAC, a bypass plate can help deal with idle and surging issues.

Good luck.

 

[R.J.]

I am not sure about the fox t-body but if it has a screw to adjust the butterfly in the t-body, this is where you want to start. Because once you decide how much the butterfly stays open, your computer can not change that, then your IAC and TPS get set off a “constant” mechanical setting.

 

[HISSIN50]

I am not sure about the fox t-body but if it has a screw to adjust the butterfly in the t-body, this is where you want to start. Because once you decide how much the butterfly stays open, your computer can not change that, then your IAC and TPS get set off a “constant” mechanical setting.

Right. The IAC is out of the equation on setting the fox idle (it is done on a hot motor, with the IAC disco'd). The idle stop screw is adjusted, then the TPS is checked/adjusted. Once all is good, the IAC is reconnected. With no load on a hot fox motor, the IAC should not be needed.

 

[urban96]

Try setting your idle with the procedure below. It is a mechanical and electrical adjustment so the computer is forced to learn the new setting instead of just slowly setting it back! It worked for me and my buddy after his TFS H/C/I

MECHANICAL IDLE SETTING

'94-'95

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC. You are done.

ok i tried this method this morning and had it idleing at about 850-900 with the IAC disconnected and when i shut it off and re connected it and started it back up idle dropped 100 RPMs is it supposed to ?

 

[R.J.]

I would clean your IAC and do it over. If that does not work, set it 100 high before you plug the IAC back in.

 

[urban96]

how do i go about safely cleaning my IAC, ive read about people damaging theirs trying to clean it

 

[R.J.]

I use brake cleaner, cotton swabs, paper towel, and lower pressure air. But you are right it is not easy and really easy to break. I've broken one and it was not even mine. If the little fins inside break or spin your idle will shoot up to like 2500!

 

[RIO5.0]

WD40 and swabs works as well for cleaning the IAC....If its an old one you'll be amazed how much crud there is...keep swabbing and flushing it til it comes out clean..