I have an 87 IROC with a 5.7 tpi the car idles perfectly smooth with the wire disconnected that you disconnect to time it.When you plug it back in it starts missing again.The miss is only noticable at idle and just off idle in park.I have now replaced the following since buying the carlugs,wires,cap,rotor,ignition module,distributer,fuel injectors,egr valve,egr solenoid and egr temp sender.I replaced the egr system because I was getting code 32 and the injectors because they were leaking down making warm starts difficult.The car runs very strong and has a rebuilt engine about 15000 miles old,also I am no longer getting any codes.Any suggestions?

 

might be a bad ESC (electronic spark control) unit.