just wondering if anyone has come across this problem? My trailblazer will not stay idling at stop signs or red lights but seems to run fine besides that..does not happen all the time but very intermittent? Help please point me in the right direction...O

 

I would start by cleaning the TBI...

 

That is how are's started a year ago. We were told we needed a new timing censor 800 plus dollars later we had to replace the spark plugs 2 months later because they were miss firing, again 3 months later. Now it is all out of time and we do not know what to do. It runs really ruff with the a/c on or in the morning and early afternoon hours but better at evening hours. It is miss firing and no one knows why. We wish we had answers too.

 

What is TBI?

 

It's possible you have a bad idle air control valve, or a vacuum leak. Is the check engine light on?

 

throttle body injector

 

change your timing chain tensioner...that's what I did to my 2002 trailblazer and its running perfect now.