my '94 z-28 six speed would misfire and buck under load below 2000rpm. I pulled the optispark and opened it up. There was obvious crust build up on the terminals and redish colored light crusty trails leading away from the terminals. This car has only 26K miles and I suspect this condition was accelerated due to the high electrical load because I had installed a crane HI-6 ingnition module required by the Vortech supercharger installation. I think these high voltage muti spark systems may reduce the life of the optispark. I found a great source for the optispark for only $282 for new GM part Dallas Slabaugh 877-448-5451. I pulled the Vortech system, I have not been happy with reliability and service from Vortech. My new direction will be mild cam and limited mods. to gain resonable naturally asperated performance with excellant reliability.

 

I'm also having a small stumble at idle and low rpms. think it's the opti. already replaced coil and fuel filter. but i'm replacing the opti when I do the cam install. hopefully that helps

 

I checked the fuel pressure. then ruled out the coil and MAF by swapping paets off my other Z-28. I may have been able to replace the cap and rotor for $200 to fix the problem on mine but it did not make sense to take the risk because the complete unit was available for $282. Make sure your plugs or wires are not the problem.

 

I just did wires, it could be plugs but since i'm doing a cam swap etc..i mine as well replace the opti