One thing I ran across on my 89 is low coolant level. It sounds wierd, but the auxillary air valve is coolant heated. I had low idle and stalling prblems until I found out I was low on coolant. I'm guessing air pockets in the auxillary air valve make the idle funky. I never really figured it out. Earlier re's used a different auxillary air valve, so I don't know if they operate the same way. Also, along these same lines, make sure the engine is truly at operating temperature when you adjust the idle screw. Otherwise, when summer comes it will definietly idle low. Good luck.
Yeah, I know that. My truck isn't holding coolant well at all, it's all being blown out by back pressure. I just want to step the idle up until I get my coolant issue fixed.
