Join Date: Sep 2009
Location: Brownsville, TN U.S.A.
Ok, this one is out of left field, but check your intake. The throttling up and down and crazy gauges happened to the LT1 in my Z28 once and the problem was the intake had come disconnected from the plenum. If it's disconnected reconnect it and unhook your battery for 15 minutes.
Yeah, it's out of left field, and does not explain it all, but it's easy to check. Honestly though, I also think you are looking at a ECU.