My 1994 LT1 has developed a miss under 2000 rpm under heavy load. Above 2000 rpm at full throttle it runs strong with no sign of a miss. I suspect carbon traces in the optispark.When it miss fires under laod there is an occasional ping and the car bucks. Has any one experianced this type of failure mode of an optispark or other suggestions of what I should check before I pull the water pump and lay out big $$ to replace this poorly designed piece of crap?

 

Before you go out and spend some big money check the plugs, wires, coil, and coil wire. The coil and coil wire usually are bad with a high RPM miss but it wouldnt be bad to check those out. Do you have any codes?

 

Honestly, my low rpm sputter was caused by a dirty MAF and a dying fuel pump. Test your fuel presure. Also replacing coil, wires,plugs can help also. You will uslly get an SES light if you have a misfire, I thought it was my opti when I had my low rpm sputter but it wasn't and I replaced mine.