Re[2]: Vac advance?

[jmbrodsky@domain.elided]

     Tom,
     
        Check the vacuum advance can, by putting a piece of hose on 
     the can (~3 ft.), and while the engine is running, suck in the 
     hose and look at the timing light.  If it works, it works, if 
     not, you'll know.
     
        This sounds like your problem entirely, with the stumble that 
     is.
     
        The EGR Performs two functions, the latter being minimal.  It 
     recirculates exhaust gasses into the combustion process to 
     re-burn, any unburned flammables/volatiles.  It also serves to 
     slightly warm the inlet mixture, but only slightly, the manifold 
     crossover does a better job of this.  It's only required for 
     emissions, NOT runnability.
     
        Wow, 5 MPG!  Worst I ever got was 7-8 with a 345!  Basically, 
     my truck runs as good as the day I bought it (the PO used to 
     'take it in' everytime it whimpered, so it was babied for it's 
     Arizona life).  Basically it hasn't changed in the running, so my 
     belief is that that vac advance NEVER worked, in 8 years.
     
        Keep your foot out, and always be the LAST one from the light, 
     and you'll get 14 mpg easy.
     
        Good luck,
     

     -Joel Brodsky
        www.physics.arizona.edu/~jbrodsky

         '76 IHC Scout II 345/tf727 RE8000, Cibie40s, custom 
                rear tire rack, 6 different color body panels.
                Not much sport, all utility.
         '75 IHC Travelall 150 4wd 392/tf727 Hummer brush guard, 
                3/4T rear springs, Hella Rallye 2000s, Con-Ferr 5x7,
                Class IV hitches front and rear, 3" Exhaust.
                1st Place, Rocky Mountain IH Rendezvous,
                3rd Place, Tulare IH Western Regionals.
         '74 IHC Travelall 150? 2wd 392/tf727 "The 'new' one"
                Factory AM/FM, Cruise, Tilt, AC, Captains Chairs,
                Rblt, Alt, carb, fuel pump, ps pump, water pump, dash,
                seats, rear door, starter, master cyl, what could be left?