OK the other day I let my brother in law borrow my car. He was driving down the mountain and said the car just up and shut off and won't start.

It's a 96 z28 mostly stock except shorty headers and a msd optispark

The car isn't throwing no codes at all except for what was already there. So far we replaced the coil, ignition control module, fuel filter he says it's not throwing no spark what could be wrong I'm trying not to replace the opti if I don't have to what could be wrong if all these parts are bad wouldn't they throw codes?

 

ignition switch fail will do that. mine did that and i had to hold the key at a certain position to get home. could not get it to start once home. not common for opti to go like that. not unheard of either.

 

A cheezy video, but informative. Coil and opti voltage testing starts around the 17 minute mark:

 

Does changing the opti have anything to do with the timing?

 

Only if you don't have it lined up right. There's only one way it will fit to the cam, you would have to force it on for it to be in the wrong position. There is no timing adjustment.

 

the screws come lose on the rotor of some opti's, best to locktight them before install.

 

Not trying to be pessimistic here, but if the Opti isn't working at all, you won't get any new codes because the PCM wont set any until the engine is turning (even cranking), and the Opti provides that piece of information. While cranking, the tach should jump to about 200 RPM if the Opti is providing a good low-res signal. Of course, the cable to the Opti must be good also.