name that sensor

[Anthony1238]

Ok i got an 89 sho, my question is what sensor controls the idle at code temps, I went out to my car and tried to start it and it would turn over but wouldn't stay on. the only way i got it to stay on was to kep my foot on the gas at about 1000 rpms for agout 2 minutes, then the idle was normal. i ran the codes and got a code 24, what sensor controlls this, i'm thinking it's either the sensor in the air box or the Iab valve.. any ideas?

ohh yea it only happens when it's really cold out

<small>[ November 26, 2003, 10:46 AM: Message edited by: Anthony1238 ]</small>

 

[twr]

Code 24 is the ACT sensor - it will trip a code if the temp outside is 50 degrees or colder, so I would ignore it. Sounds like you need to clean/replace the IAB valve.

 

[Anthony1238]

I cleaned it about 3 weeks ago and nothing seemed to be clogged, the switch also opens when 12v where applied to it. but i will try to find a new one. any more sugestions? i just want to narrow it down.

 

[twr]

You might try cleaning the MAF. During warm up, that's really the only sensor that functions to tell the PCM how much air is going into the engine.

 

[projectSHO89]

While you indicated that you pulled codes, I have to ask if you also read the KOER codes. There is a portion of that test that checks for proper idle control. Specific codes will be set if the computer fails those tests

The IAB is primarily responsible for maintaining idle under the control of the computer. Of course, the computer has to have correct inputs from several sensors in order to achieve this control. As mentioned, the MAF is one, the TPS is another.

Cleaning the old IAB is often ineffective.

AutoZone sells a suitable replacement for arounf $55. Their system refers to it as a "Throttle Air Bypass".

Steve