My buddy has a 94' Formula and here is what he has changed:

Plugs
Wires
Coil
Module
Opti
Fuel Filter

Okay but here is the kicker: When at WOT it hesitates at 5500rpm but if he does 3/4 Throttle absolutely NO issues, he can run it up to the rev limiter.

We think it has something to do with Fuel, but we can't seem to figure it out. He is currently going to school at UTI (Mechanic School) and has hooked it up to every damn scanner that the school has and it reads everything fine with fuel.

Most other posts I've read have had this issue at WOT but he doesn't have it at a lower throttle response.

Any ideas?? PLEASE!

 

He might want to check the fuel pressure to the rails. ALso he might want to have his injectors cleaned out.