Hey I have a 95 z28 and I am having a misfire on cylinder 2 and 7. I have replaced the opti, harness, coil, plugs ,and wires and am still having the same problem. Also checked the injectors and they are working.

 

Bad Opti?

 

idk this is the second opti and they were both delphis so i dont see how they both would have the same problem

 

any codes?

list them all please
and some more information about your car and what you have done to it would help as well, maybe put that information in your sig so you dont have to list it every time you ask a question

 

well the light isnt on and its a 95 6 speed all stock for the most part when i put the first opti in it ran great for a few miles then started missing. It wasnt sending spark to 2 or 7 so i warrantied it and just put the new opti in and it has same problem.

 

where are you getting your opti's from?

no codes at all though?

did you change the cap and rotor also?

and again, information about the car and any modifications would be awesome, but thats only if you want us to help

 

im getting my optis from rockauto.com i got the delphi and its not putting the engine light on but i cant check the codes bc i dont have obd1 scan tool. The car is all stock no aftermarket mods except for msd coil.

 

....

 

and no i didnt change the cap and rotor i just got a whole new unit

 

Have you checked the compression of at least those 2 cylinders? The right way?

 

The codes for the Opti optical sensor do not turn on the SES light. You have to scan it.

 

i didnt get to check compression yet and i will see what i can do about getting a scan tool thanx for the help

 

How do you know those cylinders are missing?

 

i pulled the injector connectors and listen to the idle

 

ok so i spark tested it and its not sending spark to cyl 2 and 7 but the other opti did the same thing so i doubt 2 different optis have the exact same problem so im guessing the pcm. any thoughts?