i bought this 94 z28 with lt1 put a tranny in it and it was driving fine. Then i went to town one day and it died and wouldnt start back up till the next day. i pulged it in and it had a high res code . Now it only tries to fire every once in a while. this is what i have changed starter,coil,icm,fuel filter. i dont know what it is maybe opti spark???? or pcm??? Has anyone had the happen before? i need help plz?? I also checked the harness to so i think its the pcm. And should the high res wire have a signal?? mine doesnt thanks David

 

High res pulse is generated by the Opti.