For those troubleshooting a high idle, here is my experience...in summary.
High idle fluctuated from \900 - 1100
I continuously tried to locate and fix vacuum leaks, but the did not drop the idle. Yes, I adjusted idle speed screw, fuel mixture, timing, etc.
I finally tried tapping on the egr valve with a large screwdriver and like bingo, the idle dropped down.
I haven't replaced the valve yet. I pulled it off and cleaned it up with brake cleaner (being careful not to get any in the diaghram side of things), and then applied some silicone and graphite powder to the shaft inside.
It still has the sticking issue, and so for now I just disconnected it from the modulator. And it runs great.
lesson learned: check for leaky egr valve during idle troubleshooting. A solid tap with driver should seat the valve.
High idle fluctuated from \900 - 1100
I continuously tried to locate and fix vacuum leaks, but the did not drop the idle. Yes, I adjusted idle speed screw, fuel mixture, timing, etc.
I finally tried tapping on the egr valve with a large screwdriver and like bingo, the idle dropped down.
I haven't replaced the valve yet. I pulled it off and cleaned it up with brake cleaner (being careful not to get any in the diaghram side of things), and then applied some silicone and graphite powder to the shaft inside.
It still has the sticking issue, and so for now I just disconnected it from the modulator. And it runs great.
lesson learned: check for leaky egr valve during idle troubleshooting. A solid tap with driver should seat the valve.