My 78 Z idels rough, dies, and backfires. I have been checking the fuel delivery parts. When i checked the wiring harness from inside the car I didn't get a reading on the air flow meter. I removed the air flow meter and checked it i did get a reading. I am going to double check from inside as soon as it cools off. (temp. outside) If it turns out to be the harness where can i get a good harness. If my problem can be caused by something else please let me know. (New fuel pump, filter, cold start valvue)

It could be any number of things, alone or in combination. However, your air flow meter certainly sounds like one issue. Try using a contact cleaner, both on the connectors and on the contacts inside the air flow meter. (Open it by carefully prying off the black, plastic cover on the side.) In a pinch, WD-40 works quite well.