I hope somebody can help me here because i am stuck. Under normal driving conditions the car runs fine, even under 3/4 throttle acceleration it runs and pulls hard. Under wot is when it has the problem, it pulls hard till around 5k and then it stutters almost like its on the rev limiter. It was an on again off again thing but now it wont go away. I went to the track sat and made 5 passes and it did it every pass. My current mods, 355 with stock ported heads, cc306 Cam, SLP Shorty Headers, Delteq Ignition....... Could I have a coil pack breaking down? Also, my front seal is leaking oil into the opti, howver there is no high voltage going through the opti it is just used for timming and tells the delteg when to fire, could this be causing a problem?? Thanks in advance for the help

 

Its either not getting adequate air supply or the optispark is going bad, I would suggest the cheaper alternative first via the induction system. My dad had this very same problem on his truck.

 

high rpm miss could be a number of things which mainly boil down to air or fuel related

things to check would be plugs, wires, ICM (not sure if delteq kit retains it tho), optical sensor, injectors, fuel pump, etc

first thing I'd pop the hood at night and look for arching, second I'd read the plugs and look for anything unusual while replacing them, another test would be to attach a fuel pressure gauge onto the schrader valve of the fuel rail. you would look for 40~ psi with key in on position, 40~ psi @ idle, and around 43~ psi at WOT without any pressure drop.

 

On top of this, checked your air filter real quick, somehow mine got so dirty between changes it started cutting out near red line, after doing my method of "buy performance parts till you fix it" I discovered it was the filter and replaced with a CAI.

With that being said, my money is on the fuel pump.

 

Sounds like what mine did when the fuel pump went. Get a Racetronix one when you go in there to replace it.

-Dustin-

 

My high RPM miss was the opti, but you're not using the HV part. Start checking your wires. Mine acted exactly like yours, felt like hitting the rev limiter, mine was at 4.5k. I'd say it's probably ignition related. Start the car at night and see if any of the wires are arcing. And definitely do a fuel pressure check at WOT and see if it jumps around.

 

i say plugs and wires too. i had a fried coil wire which made my car feel like it was hitting a rev limiter at 4500rpms. if its not that, check there it no intake restrictions, read the sticky on checking the opti, then check fuel pump. plenty of forums on how to do all of that.

 

This happened to me my first time out to the track with this car. MSD blaster coil fixed the problem.

 

I'm going with a bad coil pack. Not uncommon for a single pack to fail vs a single old school coil. Check your wires for a light show as mentioned above.
First thing you need to rule out would be a fuel pressure issue. If its not fuel....then its an ignition problem.