[steelybill]

One thing I would add to what you have already done, is check the fuel pump pressure. There is a capped-off port in the fuel line, not far from the TBI where you can plumb in a gauge. The book sez the pressure should be between 9 and 12 lbs at that test point, in all speed ranges.
Some mention is made of the port in the manifold that the EGR valve is mounted on, for a build-up of "stuff" in that port.
Also hoses to the MAP sensor and really, all vacuum hoses for visual condition.

The spray pattern of the injectors can also have an effect.. In a throttle body, with the air cleaner off, the spray pattern from the injectors can usually be seen to some degree

Hope this helps.......

BILL