Second post regarding this. 93 LT1, auto, 92 k miles, new ICM, coil, no loose grounds or wires. Location is eastern PA so its cold. Car will start fine and idle smoothly with no apparent cyclinder drop. Drive less than one mile back in driveway, put into park, it idles then dies instanly - no chugging - just dead. Will not restart for 1-2 hours then does the same thing. I checked spark the last time it died and its getting spark using number one plug wire and a spark plug. The optispark is original along with fuel pump. I do plan to replace water pump, hoses, plugs wires, opti and fuel pump in the spring howver would still like to know what the problem is.

Thanks

 

My experience the opti fails when gets hot and is fine after cool down but will do the same thing after it heats up again.

at the top of this forum there is opti diagnosing.

 

A heat soaked ICM will also act that way. But a heat soaked Opti or ICM will not produce a spark.

Rather than guess, start by scanning it for codes. If its the optical cam position module in the Opti, or the ICM it will set a code.

Note that the fuel pump can also overheat if it's near the end of it's life. Since you have spark, check the fuel pressure.

 

I am not getting any check engine lights but will run a scan to see what is logged. Also the ICM is new and not sure the car runs long enough to get it hot or heat soaked. Will check fuel psi once again after it dies.
Thanks