After sitting for two years my 93 Z28 will not start. The speedometer registers while the engine is cranked. I've never noticed that before. Also, mice nest material blew out of the exhaust pipe when engine is cranked. It acts like it is going to start the first time you crank it, shows no signs of life after that. Thinking exhaust may be plugged but speedometer registering (up to about 80mph) has me stumped. Car has new fuel pump and has good pressure.