VandykeT/A

A guy I know bought a 94 Z28. Car runs fine during normal driving no misfires at all. Not even the slightest hiccup. At wot its smooth as well until around 4500 rpm its like it hits a rev limiter and it won't shift out. It does it religiously between 4500 and 5k. He floored it 3 times and it done it everytime. I've searched and I've come up with ignition coil, opti, or the rotor screw backing off. I'm curious if anyone else has any ideas of what else to try. The guy wants me to try to fix it. I'm going to check plugs, wires, fuel pressure, and swap coils. Anyone know of any other common things that happens to these engines to cause a high rpm misfire?

02sslayer

iTrader: (4)

I am having this same exact issue. Car runs fine at cruise(for a big cammed car)
But when I accelerate hard it starts to miss, spit and sputter. I also get a flashing po300 code. I will let off the gas and the car will continue to run rough for a few seconds and then it's fine. I have had this problem for quite a while now. I have changed plugs and that worked for a few wot pulls but it started doing it again. So I changed wires and changed coil packs around. One scanner says multiple random misfire and another scanner says #8 misfire. Im thinking about changing out the following:
Cam position sensor
Crank sensor
And 02 sensors

These are just 3other things that I have heard can cause this issue. Anyway, did u ever figure out the issue? Your the only person I have seen on here so far that has the same exact problem as me. It's even at the same rpm range

SS RRR

iTrader: (2)

If it runs fine until a certain RPM I would also check valve spring pressures.

blkchevyz

might need a new fuel filter, seen that same issue before.
also take a look at the coil wire, make sure it doesnt have alot of buildup on it.