Hey I’m just looking for any suggestions as to what may be going on with my 1985 Camaro z28. Currently it’s cranking and not starting it just died idling one morning. It didn’t have spark so I replaced the icm now it has spark but still won’t start. I checked the valve on the fuel rail and it’s getting fuel to the rail. Another thing I noticed is that the tach never worked and now it moves around from 4,500 rpm to 7,000rpm while cranking. I’m new to the the third gen platform I’ve don’t have any experience with them or chevys I’ve only ever had fords so any help would be appreciated thank you

 

Sounds like you need to go through the ignition troubleshooting steps. The module in the distributor is a prime suspect on these 80's machines. Most auto parts stores can check it for you. While you're at it, ohm out the coil and make sure there is continuity through the center post of the distributor cap to the rotor contact point.

 

It is recommended to replace the coil whenever you change the ICM. A bad coil can lead to the ICM wearing out much faster than it should.