Replacing Idle Air Control Motor 93 Century (V6)

11-26-2011, 02:42 AM
Can anyone please walk me through to replacing Idle Air Control Motor for 1993 Century (3300) engine please?

Step by step detailed instructions would be nice. :-)

-Thank You

11-26-2011, 08:42 AM
there are 2 screws that hold the iac to the throttle body and a 4 wire square electrical connector.its the only 4 wire connector there.the throttle body is where the air enters the intake.go to and enter vehicle for repair into.real easy to replace.remove 2 screws small make sure dont drop or lose remove electrical connector...has a lock tang pry out on first and pull and wiggle and remove connector then just wiggle and pull on iac to remove.iacs usually last forever they sometimes have to be removed and cleaned the pintle of carbon and clean iac passage also and dont forget to clean throttle body linkage and butterfly with carb cleaner or intake cleaner or even brake clean.what type of problems are you having?I have seen people replace and spend hard earned money to find out that is not their problem.

Tech II
11-26-2011, 08:56 AM
3300 or 3.1?

As Autojoe asked, why the replacement?

11-26-2011, 04:54 PM
Hey autojoe,

I went to Firestone to do some diagnostics and came up was the IAC. In the morning when I first start it it revs like a normal car does then it the check engine lights comes on then it revs high. after full warm up it the light goes away but the engine still revs high. after you park and start it again this time its normal idles lower but rough.

Firestone said that it was the IAC and they wanted to charge me about 290.00 to do it. I figure I could work on it myself and save money. Can I just clean it out or better just replace it?


11-26-2011, 07:20 PM
on that year car 1993 with 3.3L engine the computer detection of a problem is very limited.maybe a code 35 idle speed error.this code may set if actual idle speed is 300 rpm above or below the desired idle speed for 50 seconds.can be caused by a faulty iac but other things can cause this can use scan tool bi-directional controls for testing iac if that year would allow or use a special iac tester where you disconnect the iac electrical connector and hook up tester and start car and move iac pintle back and forth and see if idle rpm changes when pintle moves....if not then the iac is bad.also there are iac noid lights to test the computer control of the iac.I dont know what kind of diagnostics they also look at iac steps on scan tool with and without load.if you are going to take their word and buy an iac and install and problem still exists after installation.....then you are on your own.....carbon buildup in the iac channel could impede movement of pintle of iac but it would have to be pretty bad..would have to remove and clean iac passage and the re-install to see if it helped.worth a shot.Do you know what code was retrieved by them when they did diagnostics?I think there is one iac code unless other code relating to another sensor.sure a faulty iac can cause the symptoms you autozone you will pay probably around 80 dollars.easy to install....about 20 minutes.let me know.joe

11-29-2011, 12:49 AM

Well the code on their machine came up AC14 IAC motor. on this 3300 engine the IAC which I believe on behind the intake because the MAF i see is on front.. IAC is the opposite side end of the MAF.

by chance would you happen to know the vacuum hose sizes used on that engine? or a reference book I can buy. In my experience Haynes and Chilton dont really give you a standard size listing.

Thanks again :-D

12-20-2011, 05:53 PM
I think some of them are 1/4". Recently, the line for the fuel pressure regulator busted and Autozone just gave me about a 1" length of it.

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