IAC problem

GSMS1968

MEMBER
1999 LEXUS RX 300
3.0L
6 CYL
AUTOMATIC
94,000 MILES

The car would not idle very well about 400 rpm's. I cleaned the IAC valve and got lots of carbon out of the unit, but now it idles at 3200 down to 1500 and over and over I ran the air conditioner and it stays at 2500 or a little less. I cannot get it to go any lower. It has 12.4 volts key on and a good negative to coil. I unplugged the IAC and it did not lower the rpm's. I can remove the coil and manually operate IAC valve to desired idle. I am assuming it needs to re learn, but I tried for a hour or more with no luck.

4 Replies

HMAC300

MECHANIC
48,601 POSTS

Clean the throttle plate on both sides as well and check for a vacuum leak or cracked hoses etc. If it continues scan for codes. Most auto parts do for free.

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Tuesday, May 24th, 2016 AT 6:28 AM

RENEE L

ADMIN
1,257 POSTS

Hi Gsms1968,

Here is a link to an article that features written step by step instructions and pictures explaining how to do the scan yourself, also I have included a link to our YouTube channel with a how to video on code scanning. Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com. Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Thank you for visiting 2CarPros.com.

Kindest regards,

Renee
Admin