Okay, so I got my new TBI installed and fired it up, got the timing and idle set. The O2 sensor is currently disconnected because the harness I bought had the wrong connector, so I'm plunging ahead while I wait for an adapter in the mail. Anyway, it runs okay, but once it heats up, it starts surging in and out at a very periodic interval. Every 6 seconds or so, it'll go from 650 to 800 RPM and back. I put a light on the timing, and it doesn't seem to be moving around. The only way I've found to make it stop is to remove the vac line from the MAP and plug it. Then it runs fairly smooth. Any ideas where to start looking?