my one barrel 1989 b2200 is only get 20 miles to the gallon, good tuneup, good tires, new filters, is this normal, or what else could be the problem

 

my 22oo motor has about 30k on it now and with a weber 32/36 and header im getting 19-20 around town.... this in a 87 2000 extra cab body with a rebuilt tranny 5 speed and new u joints in the d shaft

 

The B2200 brand new was only advertised to make 22 mpg in the city and 24 mpg on the highway. Considering the thing is 16 years old I think its doing pretty good. The Page below gives stock specs for the truck:

B2200 Truck Specs

Probably in order to get any better gas mileage you will need to do some modifications. Probably the cheapest and easiest mod to make would be to upgrade your ignition a bit. You could get an MSD coil with some performance ignition wires (I prefer Taylor spiro-pro) and that should give you about 1 or 2 mpg. When you do this though you will need to gap your spark plugs .005 or .01" more than stock otherwise the increase in voltage and drop in resistance will spike your coil and burn it out in about a year. I think I'm running between .040" and .045" plug gap. I would also run a couple of tanks of STP Carb/Injector cleaner. This will help free some of the moving parts in the carb and get some of the carbon out of the engine.

At one time I had my truck getting about 30 mpg, but that was with heavy mods and ironically it wasn't emissions legal even though it passed emissions with flying colors.

K6