Drove my Merc 40 miles to my favorite car show and 3 miles from show my Merc idle speed jumps to 1500 RPMs. After parking I take breather off can't find any issues, leave car show 5 hours later and still idles 1500. Drive 3 miles outside of town and Merc fixed itself, all is right again. Go to dinner that night and car idles 1500, leave restaurant and all is well. This Merc is Possessed right? When idles increases to 1500 the overdrives does not work.. 292 T85 3 speed.
Worked on the distributor lately? I had a screw too long in my distributor plate that was hanging the distributor at advance causing fast idle. I don't think it was 1500, though. Maybe the engine doesn't slow down for the OD to engage.
The Jalopy Journal
