Might be a bit foreign, as many here have MT's, but my idle is all over the board.

I have an AT with AC, and can't find a happy medium. Set it between 750 and ~950 rpms in Park, won't idle well in gear. Turn on the AC, even worse, probably kill the motor. Set the idle to run well in gear and/or with AC on, idles between 1500 and 1700 in Park. Cold idle even higher. WTH???

Yeah, I know the damn AC idle up valve is supposed to help with AC on, but that's another Japanese mystery. Replaced everything, tested everything, nothing happens though all checks out fine.

Can you tell I'm frustrated???

 

Seafoam...give it a shot before you start replacing things even do it twice.

 

Newer rebuild, ~10k miles. Professionally clean TB, intake plenum. Brand new injectors. Tank clean and fuel pump new. New fuel filter. All ignition parts new. Passes smog with flying colors.

Although I've used SeaFoam in the past, successfully, I don't know that it'd do much here. Thanks for the consideration, though. Am I off with my thinking about it?

 

Oooo Didn't realize your sig stuff was new stuff...That makes for a more interesting time. When did this start?

Hows about this? Check your timing, did you set it with the jumper in?

 

Timing's at 6deg, jumpered, per Engnbldr's recommendation. Already tried advancing/retarding to see how it reacts. Nothing significant to report.

 

I found a plug in one of my vaccum lines (in the metal section of the line between the manifold and valve cover). Once i got that unclogged, my truck went from idle all over to smooth idle.

 

How did you find the clog and how did you clean it? Soak it in parts cleaner?

 

I'm interested, too.

To clarify, though, my idles isn't necessarily up and down, just very different from Park to Drive with or without AC.