One cheap thing you might try.....worked for me once......get under the truck while it is idling and pound on the converter with a hammer. If the thing is clogged, you might hear an rpm change with the jolts.....have someone you trust keep their foot on the brake.

Clogged converter symptoms are a slow reving motor under load.

Also, doesnt the TBI run 12 psi fuel pressure.....more than a carb fuel pump.....