'89 F-150 idles at 1,700 RPM driv'n me crazy!
 

I would like to know if anyone would happen to know what would B causing my 1989 F-150 (with 5.0 5 speed EFI and all bone stock) to idle at between 1,500 and 1,700 RPM? It's driving me crazy and I'll wear out my clutch in no time! I've tried unplugging various things to no avail.....any suggestion would greatly B appreciated. If you know of a part I need to check out, please describe what and where it is. Thanks

Richard