VARIABLE Air Intake Control Servo & Air Intake Control Valve

[zgwforum]

To be clear, I am not referring to the ISC Server stepper motor as found on the passenger side of the motor shown here:

Idle Speed Control ISC / IAC Servo All 3S - Mitsubishi 3000GT / Dodge Stealth Parts

I have also included 2 attachments which are pages from my 91 Dodge Stealth Service Manual. The item I am not interested in is shown as item L in my second attachment.

The Variable AICS is located on the driver side and is connected to the air intake control valve position sensor. In my 91 Dodge Stealth Manual this is shown on page 14-42, item J.

If you remove the VAICS, what you will see still on the engine is a nylon gear. This nylon gear is attached to a rod which runs through the intake manifold plenum. If you look on the opposite side of the plenum, you will see a plug, which houses the far side of this rod.

This rod has 6 individual/isolated throttle plates on it, one for each cylinder. The position of these plates(open, close, somewhere in between) in the plenum is controlled by the servo gear. The servo gear is metal.

When installing the VAICS, if the gear is not correctly positioned, the metal teeth will strip the nylon gear on the rod. Once the nylon gear is stripped, the servo cannot rotate the throttle plates(you shouldn't have to ask me how I know this), and performance suffers. (The throttle plate rod is spring loaded, so if the gear is stripped, the plates default to a full open position(again, you shouldn't have to ask me how I know).

Does anyone know the proper way to install one of these?

[Steve '92ES]

Yup, the VIC motor. Install it with the motor pointed up then rotate it down into position so that it turns the nylon gear into place as you go. It should stop right as the bolt holes line up. If it doesn't stop in the right position pull it out and try it again in a slightly different spot.

[zgwforum]

Thank you for this response. In appreciation, I would like to add the following:

If you need to replace the nylon gear, it is mounted to the rod by a spring pin that runs through the base of the gear and rod. Unless you rotate the gear, you probably will not be able to see the pin. You need carefully remove the pin to:

1. Prevent damage/bending of the rod
2. Prevent damage to the ROD's SEAL at the intake.

I haven't figured out how to do this yet. But I will be trying to press/push it out as opposed to hammering it out....unless I get desperate. I will post pictures because there does not appear to be a lot of information about this vital component.

Also, I am unaware of anyone who carries the plastic gear as a replacement part. Perhaps if someone is aware of a replacement and a part number, they could post it here.

As an additional piece of information, each throttle plate(6 total) is mounted to the rod with 2 philips screws(12 total). To remove the rod, you must remove the intake, and then remove these screws from the rod to remove the plates. These screws are VERY SOFT. Even with KROIL, my penetrant of choice, and the proper fitting screw driver, I stripped the heads off of half of the screws. If you do not have replacement screws, I recommend "breaking" the screws from their set position with a plier. Once the screws are broken, if you use the properly sized philip screwdriver, you will probably be able to reuse 10 of the 12 screws.

zgw