5.0lxstocktrnk

Well I have a question about my stang I can't figure out and I need your help please.

In 2nd gear under heavy throttle at around 3500 to 4000 rpm I'll get a hesistation or miss. Slight throttle in these ranges, the rpms climb smoothly. Any other gear is fine with partial or full throttle.

specs on car: rebuilt 306 wit ported gt-40 iron heads.70mm Throttle body Comp cam roller. 65mm mass air(calibrated to 24# ink). gt-40 tubular intake. 24# inj. stock fuel pump. adj fuel pressure regulator. set at 30psi. New denso spark plus gapped at .054. Ford racing wires 9mm. 5spd (T-5)

My ideas:

-fuel issue(maybe raise the fuel pressure)
- vacc leak somewhere. Possibly in the intake. I've had the same issue with my other car.
-ignition(car has new plugs, wires are in decent shape, 1 year old coil)
-maybe valve(s) floating.


I'll appreciate any suggestions.