No Idle

[Musada]

The weirdest thing has been happening to my car for the past 2 weeks....In my 1990 LS 400 the check engine light comes on and it seems to run fine, but after driving it a while the check engine like will go off, and it will no longer idle on its own, i have to keep my foot on the breaks while giving it gas. And then the check engine light will come back on and it will idle just fine once more. Any ideas? I hear its the throttle position sensor. What do you guys think.

[SRK]

Because the check engine light has been illuminated, there will be a code in memory, and that will tell you the affected component(s) so you don't have to guess. Have it scanned and go from there.

[steve2006]

Or grab a paper clip and diagnose it yourself.

http://www.lexls.com/tutorials/intro/codereading.html