I have a 1989 IROC-Z with a 5.7 Litre TPI Engine. The car had been setting for over a year and when I started it the Tac Pegged at 7,000 RPM and will not work and does not return to Zero when shutting the engine off. All other Gauges work correctly. Any Ideas? Also, when driving at 20 MPH and flooring it it will not kick down to First Gear. At 50 MPH and flooring it it kicks down correctly to Second Gear. Is the Kick Down Issue Tac or Transmission related?