I put in my cam heads the whole deal. ...... misfires like all HECK! I work at a Chevrolet Dealership and its in service right now they are trying to figure out what is wrong....

Just replaced OPTI ----> No better same thing
Replaced plug wires and plugs ----> Same thing
Replaced Coil ----> Same darn thing

its getting a 300 code on cylinders 2 and 7



Someone please help!!!!!

1997 z-28 6 speed, AFR LT4 heads, Intake manifold, CC306

 

I just did my heads/cam/rockers/optispark, and when I first started the car, it misfired too. At first I thought I did a mistake with timing or opti spark, but all that was wrong was too tight rocker arms. If you put a bigger cam, probably you will need to loosen up your rockers even if you didn't change them. If you could get your spark plugs out, then you could turn the engine by the crankshaft hub and see how easy the engine turns.

 

You have an OBD2 car! It has got a crank position sensor, that is supposed to detect cylinder misfire by watching the crank rotation speed and firing order.
Now you've put in a CC306, that must have a lope like a ****, and your CP sensor thinks it is a misfire! I don't know what can you do about it.... maybe change to OBD1..

 

or get some tuning for his OBD2... he didnt mention tuning, but tuning is DEFFINATELY neccissary with the 306 and heads.

 

The CPS doesn't have an effect on how the car runs, it just "detects" misfires. I still have OBDII and had my CPS sensor programmed out when I switched to a cloyes chain. I drove it for a while after removing the CPS reluctor ring and with the sensor still active and I just got an SES for it, it didn't effect the engine performance though. I would think he needs some programming for the new heads/cam though.