Tip-in After Boost Issues
I'm having an annoying issue which is being hard to narrow down, mainly because it only happens some of the time.
The situation occurs after a pull where the car has seen ANY boost (anywhere from 1-9lbs, currently). After the pull, i'll tip back in on the throttle, and get a large hesitation, with sounds like the car is "trying to clear its throat". Then after about 1-2seconds, it will clear out, and drive completely normal.
This happens maybe 50% of the time, and will follow anything from a slight acceleration that sees boost, to a WOT pull. It does not seem to occur ever after acceleration where boost is not achieved.
349 a4, 10.5:1 comp, ported highports, f cam, trickflow r intake
76mm precision turbo, intercooled. 90mm PMAS calibrated for 60lb inj.
a9l tuned with moates quarterhorse.
Checked the usual suspects: Mass Air is clocked properly, TPS is fine, Wideband seems to stay in an appropriate area of lean state for 'off throttle' position, no o2's. Ignition is a msd 6al, msd HVC coil, msd pro billet dist, plugs, wires etc all new. No vacuum leaks that I can find. Car is not burning any oil.
Car runs, idles, and performs great... just this damned hesitation.
Any insights or recommendations?