Missing under light load

[Slowhawk]

The car was running great today.Ran it on the dyno and got 375hp/455tq with 15lbs and A/F at 10-1.After the pull the power dropped off and started to miss at part throttle(bucking).So I changed the plugs that looked perfect and the missing went away till 2 miles down the road.

My scanmaster looks normal like TPS anf MA readings.It only misses at part throttle/light load,when vacuum is 10 inches or less the car picks up great.It idles perfect with 15 inches of vacuum like it was before.Fuel pressure is the same 45psi.

So,what should I be looking for?Coil packs?MA meter?It seems to only happen when the car is fully warmed up.It is pretty undrivable like pulling from a stop.Feels like 2 plugs aren't firing till heavy load.

Thanks

 

[BUICKTR]

Check spark plug wires, module, coil, grounds.

 

[Sleeper-6]

Check the cam sensor, I had a nasty light throttle bucking problem, It would go away as soon as I unplugged the sensor. I guess it shifted slightly, I tweaked it slightly one way or another and cured it.