Minimum Air Idle Adjustment

[XfireZ51]

There's been several threads whee this topic comes up. I had documented it as part of another thread but thought I would set it up for its own to make it easier to find. Would make a good sticky.

OK. Here goes:

As for setting the IAC count for Minimum Air, the procedure I follow is:
(Do this procedure once you have warmed motor to C/L operating temps. otherwise it may very well not idle. Also, you will have converted your throttle stop stud to a hex bolt I think a 7mm hex head.)

1. Jumper the ALDL as you would for reading codes.
2. Turn ignition to ON, not start.
3. Leaving ignition ON, remove the IAC harness connector. This fully extends the IAC pintle and closes off the IAC port.
4. Shut ignition OFF and remove the ALDL jumper.
5. Start the motor and get it to idle. May need to use a bit of throttle at first.
6. Check idle rpm. Turn the throttle stop screw until the motor is idling at an rpm just below what your target idle rpm. I want my idle at 875-900, so I set Min Air throttle at 800-825rpm. You may need to adjust TPS Voltage so that ECM stays within idle TPS Voltage range.
7.Tighten everything up and shutoff motor.
8. Plug in IAC. I also undo the negative BATT cable to drain the ECM memory.
9. Reconnect BATT turn ignition ON, and check TPS V. Adjust to .53-.57v if necessary.
10. Start motor and quickly raise to ~2000rpm for a brief period. This resets the IAC.
11. Shutoff motor, then restart. Allow motor to idle down and check your IAC counts and your TPS Volt which may need to be adjusted one more time.

[Dynomite]

Originally Posted by XfireZ51

There's been several threads whee this topic comes up. I had documented it as part of another thread but thought I would set it up for its own to make it easier to find. Would make a good sticky.

OK. Here goes:

As for setting the IAC count for Minimum Air, the procedure I follow is:
(Do this procedure once you have warmed motor to C/L operating temps. otherwise it may very well not idle. Also, you will have converted your throttle stop stud to a hex bolt I think a 7mm hex head.)

1. Jumper the ALDL as you would for reading codes.
2. Turn ignition to ON, not start.
3. Leaving ignition ON, remove the IAC harness connector. This fully extends the IAC pintle and closes off the IAC port.
4. Shut ignition OFF and remove the ALDL jumper.
5. Start the motor and get it to idle. May need to use a bit of throttle at first.
6. Check idle rpm. Turn the throttle stop screw until the motor is idling at an rpm just below what your target idle rpm. I want my idle at 875-900, so I set Min Air throttle at 800-825rpm. You may need to adjust TPS Voltage so that ECM stays within idle TPS Voltage range.
7.Tighten everything up and shutoff motor.
8. Plug in IAC. I also undo the negative BATT cable to drain the ECM memory.
9. Reconnect BATT turn ignition ON, and check TPS V. Adjust to .53-.57v if necessary.
10. Start motor and quickly raise to ~2000rpm for a brief period. This resets the IAC.
11. Shutoff motor, then restart. Allow motor to idle down and check your IAC counts and your TPS Volt which may need to be adjusted one more time.

Dominic ........Great Information and by the NUMBERS
In -Solutions- Page #4 under THROTTLE BODY AND AIR INTAKE
Air Idle Adjustment TIPS

[Roadster]

Thanks very much for posting the procedure. Tried looking up the info as you mentioned, but no luck. So this comes in very handy....

I also am assuming that the "nut" is permanently attached to the bracket and only the stud gets removed in order to thread in the 7mm hex head bolt, correct???

[Jagdpanzer]

Tom,
The nut is not attached.
Getting the old Allen set screw out can be a real pain.
Spare the drama and remove the TB and do it on the bench. If the set screw fights backing out go the other way and screw it all the way through the other direction. Be sure to hit it with some penetrating oil.

[Roadster]

Appreciate the reply Phil, sounds like the way to go....I might just try one more thing before removing the TB....thanks...

[Roadster]

Originally Posted by Jagdpanzer

Tom,
The nut is not attached.
Getting the old Allen set screw out can be a real pain.
Spare the drama and remove the TB and do it on the bench. If the set screw fights backing out go the other way and screw it all the way through the other direction. Be sure to hit it with some penetrating oil.

Phil,
Taking your advice and going to remove the TB within a few days. Hopefully I'll get it all right and idling just fine!!!

[XfireZ51]

Here's a pic of my throttle stop.

[Roadster]

Thank you sir, have seen that on mine and as said a real PIA to get to with everything attached.
Some simple questions....

1- other than removing the IAC, TPS connectors and various hoses, can the throttle cable assembly come off with the one Torx 25 screw that is above the throttle stop screw and along with the 2 cable screws attached to the plenum?
2- and since everything is still together, will the cable need to be re adjusted when assembled?

Been looking through the FSM, but couldn't find what I was looking for!!!

thanks for any info......

[XfireZ51]

Except that mine shows the 7mm hex head installed.
You need to unplug IAC harness connector and TPS connector but should be able to able to work w TB without disconnecting cable throttle cable. Obviously the airhorn comes off also along w undoing the throttle cable retainers on the plenum.

[Roadster]

Will get the 7mm hex head bolt later in the AM.
So the best way to do this is leave the throttle cable assembly attached to the TB, and remove as one unit, and just work on the TB in the engine compartment.

Another member also suggested the same.....thx....