I'm getting codes 41 & 42 on my 1994 Z28. Code 41 is "Ign System Problem Elec Spark Timing (EST) Open circuit" and Code 42 is " Ign System Problem Elec Spark Timing (EST) is grounded". Anyone know what this problem is?? I'm running a New A/C Delco opti with a New Delteq System. Thanks