I got the job done yesterday. While I was in there, I replaced the spark plugs with NGK Iridiums, put on new spark plug wires and new coils.

I was VERY surprised to find out that the plenum in the truck was still functional with the butterflies in place and hooked up. After I pulled the whole plenum, I hooked up my Mighty-Vac and drew down on the actuator...it held fine. the shaft is pretty sloppy, though. I'll rebuild it and see who wants to test it for me (jinstv).

The gasket under the assembled plenum is a pain to get aligned while you're trying to get everything out of the way and maneuver the part, but it can be done.

The truck runs like a demon now. I can't say which parts actually made the difference, but it is noticeable.

BUT, it doesn't want to idle smoothly. I may have an air leak, I may have a bad ISC, we'll see. Any tips on locating an air leak? Propane? How about any tips on diagnosing an ISC?

John B.