: questions before installing new idle speed motor



laurieH
02-14-04, 01:26 PM
Hi.
in regards to my 94 cadi sts, 4.6
I have the new idle spped motor and am ready to install it. Have a couple questions first.

There are 3 screws holdig the old one on the top two look easy enough to get off but the third one is located at the bottom of the motor and there isn't much room to work, any help here would be great. Is it easy to get to once removing the top two, or do I need to remove something else in order to geet to it.

Also, the new motor comes with a new idle adjusting screw, how far do I screw it into the idle motor??? Do I just use my old one as a model and go in that far??? I am not sure .
So I am assuming that once I get the new one on I may have to fool with it a bit to get it to the correct 700 rpms. I have heard both soides that I do need to make adjustments and that it comes factory set adn that the car makes the adjustments itslef, which is true.

Going to tackle this today, any other advice would be great, I am hoping this is easier than it looks.

Laurie

BeelzeBob
02-14-04, 10:23 PM
Hi.
in regards to my 94 cadi sts, 4.6
I have the new idle spped motor and am ready to install it. Have a couple questions first.

There are 3 screws holdig the old one on the top two look easy enough to get off but the third one is located at the bottom of the motor and there isn't much room to work, any help here would be great. Is it easy to get to once removing the top two, or do I need to remove something else in order to geet to it.

Also, the new motor comes with a new idle adjusting screw, how far do I screw it into the idle motor??? Do I just use my old one as a model and go in that far??? I am not sure .
So I am assuming that once I get the new one on I may have to fool with it a bit to get it to the correct 700 rpms. I have heard both soides that I do need to make adjustments and that it comes factory set adn that the car makes the adjustments itslef, which is true.

Going to tackle this today, any other advice would be great, I am hoping this is easier than it looks.

Laurie

You might find that it is easier to take the bracket off the throttle body and then take the idle speed control motor off the bracket to change it.

You don't adjust the idle speed control motor to achieve any sort of idle speed. The engine control computer constantly monitors the idle speed that the engine is at and adjusts the plunger in/out to achive the desired idle speed. Basically there is no adjustment required to make the ISC motor work correctly in terms of controlling idle speed. You do have to check the ISC motor for the proper clearance at full retract, though. That is fairly easy to do. Once the new ISC motor is installed cycle the key on and off several times. Start the engine. Go under the hood with the engine idling , hold the throttle lever open slightly to elevate the idle speed and simultaneously depress the plunger of the ISC motor with your finger. The ISC motor should retract when you do this. Keep the RPM elevated and the plunger depressed until the ISC motor retracts fully and stops. With your third hand quickly disconnect the electrical connector to the ISC motor to "freeze" it in position. Return the throttle lever to normal closed bore idle. The engine should idle very slowly...about 450-500 RPM and/or nearly stall. There should be about .030 to .060 clearance between the throttle lever and the ISC plunger. The exact amount isn't nearly as critical as the fact that there is SOME clearance between the ISC plunger and the throttle lever at full retract. If not, then screw the ISC plunger in to shorten it to achieve some clearance. As long as the ISC motor will retract when you do the above procedure and that there is some clearance between the plunger and the throttle lever at full retract then the engine controller will take care of the rest.

Now would be a good time to clean the throttle body, also, to achieve a new, clean baseline for the idle speed control. Just take the inlet air duct off the throttle body , hold the throttle wide open, spray the bore of the throttle body with carb cleaner and scrub it with an old toothbrush to clean the deposits off the ID of the throttle body bore where the throttle blade contacts it. Also clean the back side of the throttle body blade.

When you clean the throttle body, disconnect the negative battery cable to reset the idle learned values. There is absolutely no need to do any sort of idle learn or anything when you do this.