Yep, 2Bigblue2 is right on that black gunk. The TPS is
just sitting on the side of the throttle body, the spring
side of it isn't sealed real tight so the stuff just
accumulates over the decades.
I should clarify my idle setting at 850 rpms though. Yes,
the truck idles fine at 750 rpms but turning the lights
on high beams and the heater on high speed make the revs
drop 50-100 rpms so then it's down to 650 or so and a little
rough. Bumping it up to 850 with nothing on keeps it
around 750 with everything running and makes for a smoother
idling truck.
I agree the the combined knowledge on this site would equal
many phd's and I am very grateful to have access to this
group of great folks willing to lend their advice. <img src="/forums/images/graemlins/cheers.gif" alt="" />

High Regards All,
Indy