EEC port not working

I recently purchased the truck listed above. I knew it was having some problems; the engine was not running right, and the automatic transmission only works by manually shifting, but it only had second and third (limp home mode?). The guy I bought it from told me the injectors were just dirty and that the transmission issue was easily solved by replacing the old filter. He had removed most of the smog equipment (and the heater hoses, and some vacuum lines for whatever reason) prior to my purchase. I put 10ohm resistors in the 3 plugs and got a plug for the EGR valve. My check engine light is on, but I don't get any codes from the EEC-IV port under the hood, either with my code reader, or the paperclip method. My map sensor doesn't seem to be getting any power. I am wondering if this is indicative of a bad computer, or if there may be another problem I haven't discovered yet. Any help would be much appreciated as I am at my wits end here.