1997 Ford Probe cuts out giving it hard throttle

i am a mechanic myself but this probe has got me baffled.. it starts and idles fine, and if you rev it up slow it'll rev up fine. but if you punch it, it'll hit like 2500 rpm and cut out. our scanner won't connect to the computer, its got a new distributor, replaced the TPS, fuel pressure is good, spark seems to be able to jump a good sized gap, we checked back pressure on exhaust, replaced o2 sensors, checked cam timing, everything seems to be in order. any thoughts?